# Posts by Mac

Total # Posts: 196

**math**

Suppose strontium-90 decays at a rate of 2 percent per year. (a) Write the fraction P of strontium remaining, as function of t, measured in years. (Assume that at time t=0 there is 100 % remaining.) Answer: P(t)=(.98)^t (b) Estimate the half-life of strontium. (c) If presently...

**math**

Jungle Warehouse signed a 9-month simple discount note with a face value of $5,600. Find the proceeds if the discount rate is 13%

**maths**

If I bought a car at R349000 at 8.75% interest per year and made monthly payments of R5000 per month,what would my total repayment amount be for the car?

**trigonometry**

What is the single trigonometric function of (Cos 20 degrees) (Cos 30 degrees)-(Sine 20 degress) (Sin 30 degrees)

**Math**

50

**engineering mechanics (dynamics)**

A 500 N weight is attached to a stiff rod of negligible weight that is hinged to one end. The rod is released from rest in horizontal position and allowed to swing freely in vertical arc. Through what angle with the horizontal must it swing to cause a tension in it of 1000N?

**science**

You could use potassium nitrate to test for potassium because both potassium and nitrate are water soluble. Potassium nitrate will react with the fluoride and create a solid precipitate. Potassium nitrate is water soluble.

**Riddle**

Where C = 46, D = 12, P = 11, Q = 37, R = 17, Y = 19 what numbers do T and S equal?

**Chemistry**

4.5 moles of oxygen reacting with enough sodium will form how many moles of sodium oxide? How do you solve?

**math**

8(2x-3)-6x if x=3

**Poetry 7 - Check please!**

I got a 100%! Thanks!

**Health.. NEED HELP ASAP**

If you go to connections this is the quiz for Living with an eating disorder

**math**

Need help...my calculator and I didn't agree! 125+(5×5)+9÷3×8 125+25+9÷3×8 125+25+9÷24 125+25+0.375 150+0.375 150.375

**physics**

3.4

**Math**

He was wearing a football jersey and was talking about yardage gained or lost and what yard line the players ended up on.

**education**

have you had and disadvantages, advantages, obstacles

**education**

My other question is Which is your favorite Assessment to use? Elementary age Anecdotal Records •Checklists •Event Sampling Portfolios •Rating Scales •Rubrics •Running Record •Teacher and Child Self-Assessments •Time Sampling Of these what ...

**education**

Hi Ms. Sue, Elementary Mac

**education**

it was just in general what teachers like using

**education**

My other question is Which is your favorite Assessment to use? Anecdotal Records •Checklists •Event Sampling Portfolios •Rating Scales •Rubrics •Running Record •Teacher and Child Self-Assessments •Time Sampling Of these what are the ...

**Education**

I have a question if anyone can help that would be great!! I have to put a questionnaire together for my capstone class...How many of you use RTI daily if so how do you use it, thoughts on assessment and instruction and the future of RTI? DO you feel that its helping many of ...

**econs**

How do you think our nation’s output should be distributed according to income or according to some other standard (such as basic human need)?

**PHYSICS**

28m

**Algebra**

Carly deposits $900 into an annuity at the end of every month for 2.5 years. The fund holds international stocks, and it yields about 12% compounded monthly. Find the interest earned after 2.5 years. a.$31,619.46 b.$31,306.40 c.$4,619.47 d.$4,306.40 (I can not figure this out...

**Chemistry**

How many moles of HNO3 are present if 0.116mol of Ba(OH)2 was needed to neutralize the acid solution?

**Social Studies**

I think she is a tutor on this website but not sure

**Math**

Thank you so much for explaining that! I wasn't getting that answer at all, but I do see ho you get it. Thank you again!

**Math**

The Romascos hope to have $2,000 in 3 years for a down payment on a new pool. They invest $1,000 in an account that pays 8% interest at the end of each year. Will they have enough money at the end of 3 years to meet their goal of a down payment? What is the difference between ...

**art**

Where's question number 6?

**Math/Compound Interest**

1. Use the compound interest table to find the compound amount earned on a $5,900 deposit for 10 years at 10% compounded semiannually. _____________________________________ A. 9,610.45 b. 15,654.47 c. 3,710.45 d. 12,375.66 2. Megan deposited $6,000 in an account that pays 4% ...

**LA**

Woah I just saw all this drama right now and I am pretty sure this is a free country where people can use whatever language they want. Number two why do you people care about what other people are saying some people actually come here for help not to cheat. All of the people ...

**langage arts**

SAMI is right

**L.A.Help!!!!!!**

Hey dudes chill they asked for the answers sp all yall chill out

**p.e**

Um ms.sue arent you a teacher?? If you are u r one bad teacher

**Organic Chemistry**

The solubility of compound A in ethanol is 0.5 g per 100 mL at 0oC and 5.0 g per 100 mL at 78oC. (a) To make a hot, saturated solution of 15.0 g of A at 78oC, how much ethanol is required? (b) When the solution prepared in is cooled to 0oC, how much of compound A will be ...

**math help**

Your answer is wrong. You forgot to switch csc into sin, therefore r=3, and s=5. Now we know that tan (T)= 4/3

**math**

Compute the monthly payments for an add-on interest loan of $850, with an annual interest rate of 15 percent and a term of 4 years.

**physics**

(a) Set up two equations. One for forces, one for torques. For the first equation, which way does friction act? i.e. which way would the yoyo move if there was slip? Since there is no slip, friction must be acting *against* the intended direction of motion. For the second ...

**Physics**

390 is for a deccelaration of 4 and not of 7.the right answer is 195

**Physics**

195

**PHYSICS(HELP)**

R=(G*mp*T^2/(4*pi^2))^(1/3) Vesc=sqrt(2*mp*G/R)

**American History**

or maybe japanese, since that's in one of the answers

**American History**

well i've only got what my paper gives me. but i'd assume it is talking about chinese, considering those were the main asian immigrants at the time

**American History**

Most of the asians who immigrated to the united states in the 1850s came because a.) Of available work b.) Of the rumor of a "golden mountain" in california" c.) they were forceds to flee due to collapes of the japanese economy d.) none of these

**Prob and stats**

A card is to be chosen at random from a shuffled deck. Find the probability the card drawn is A. The queen of clubs , given that it is an honor card B. a red four, given that the face number is even C. A seven, given that the face number is prime Please help me, thanks :)

**Physics**

Thanks. Also noted that V2 would only be 275 as once the pressure in the bottle reaches 1atm, the volume inside would be 25litres. So only 275litres are available.

**Physics**

25 litre bottle of oxygen in a hospital. If the bottle is at 12 atmospheres, what volume of oxygen is available to the patient? If the oxygen is stored at 4 degrees C and used at 20 degrees, what difference does this make? (Assuming start volume and pressure are still 25 ...

**earth science**

The wavelengths are shorter in this region

**math**

Venn diagram problem P only=33-18-x B only =26-17-x C only =25-19-x 15-x+9-x+6-x+8+10+9+x=63 -2x=63 X=-3 Which means you have to work with 3 in the middle

**calculus**

Group two by two X^2(x-3)+16(x-3) (X-3)(x^2+16) For zeros X-3=0 X=3 X^2+16=0 X^2=-16 X=+or- 4i

**calculus**

Just pick a number in the region Plug back into the function Neg ans means less than 0 Pos ans means greater than 0

**calculus**

Get you started you have to start by guessing X=3 works Then do long division Answer will be x^2+12x+36 Factor (X+6)(x+6) 3and -6 are your critical values Now you have to test the different regions

**Urgent Math**

Point of inflection I agree with you

**Math**

A) log 6a / log 6a B)5(log 9b/ log 9b) B should help you with C

**Math**

Permutation You have 210 objects taken 1 at a time

**Math**

Venn diagram problem I phone only. 70 Cars only. 10 Both. 60 Neither 60 Total 200 Hope this will help you

**maths --plse help me..**

Tan30= h/p Tan45=h/q p + q= 100 Use substitution (h/tan30) + (h/ tan45 )= 100 You should be able to take over

**World Geography and History**

The ideas of _____ _____ are the basis for communism.

**Math**

A) .98(210) and .98(240) B) (210)(240) (.98)(210)(.98)(240) Percent decrease = diff in your two answer/ original (210)(240)

**Mathematics**

Use your rules of logs Log a^(1/3) - log b^3 Log (a^(1/3)) / (b^3)

**Algebra 2**

U-shape turned downward and moved to the left 2 units Inside the() moves left or right opposite the sign Outside the () moves up or down same as the sign The negative flips the curve

**math**

Venn diagram 256-78-116

**calculus**

A). (7x+ 4)/(7x-8) Domain is all except x can not equal 8/7 because it will make the denominator equal to 0 B). ( 5x + 4)/ 2x Domain all except x can not equal 0

**calculus**

Rate of change is 2 because you have a line the rate of change (slope) is constant

**Math**

5000(1+ .055/2)^(2)(5)

**Geometry**

That is what I get

**Geometry**

Mid segment=1/2 the sum of the bases LM=(1/2)(46+125)

**7th grade math Ms. Sue please**

1 correct 2 correct 3 correct 4 correct

**Geometry...HELP**

6x+16=49 6x=49-16=33 X=33/6=5.5

**Geometry...HELP**

In a rectangle diagonals are equal Set the two equal to each other and solve

**Math**

You first have to find your rate .75 = e^ (r)(10) Then find the time for half- life .5 = e^ (r from above)(t)

**math**

X=width X+4= length X(x+4)=60 You will be factoring

**maths --plse help me..**

Khan , I think your units are off 40.6666 .... Hours The rate is km per hour 1586 km / ( 39 km/1hour) = 1586 km x (1 hour/ 39 km) Km drops and your left with hours Not sure where the days come in except 40 hours is short of 2 days

**maths --plse help me..**

Distance is equal to rate times time Therefore time is equal to distance divided by rate. 1586/39= 40 2/3 hours That means it takes 40 2/3 hours to go 1586 km when you are going 39 km per hour So if you start at 10:30 and go for 40 and 2/3 hours, which is 40 hours and 40 mins ...

**Algebra**

-7(3)^(6-1) Or -7, -7(3), -7(3)(3), -7(3)(3)(3), -7(3)(3)(3)(3), -7(3)(3)(3)(3)(3)

**calculus**

This graph is a v shape with vertex at (0,0) with a ray in the first quad with slope 1 and a ray in the second quad with slope -1 The +1 sends this graph up one It does not change the curve. The -flip the v downward The 3 changes the curve. Instead of the slope begin +/- 1, it...

**math**

(X)+(3x)+(5x)=27

**algebra**

8-3(21/8)

**trigonometric problem**

Tan32=h/x Tan22=h/(x+80) (Tan32)(x)=(tan22)(x+80) Solve for x and then for h

**math**

6y-6 Distributive property

**algebra 1**

Parallel means same slope M=-1/3 Point(-4,3) Plug into y=mx+b and find b 3=(-1/3)(-4)+b You should be able to finish from there

**math**

C= 3a 3c + 7a = 46000

**math very urgent**

You will get the same answer The extra would be putting your answer in lowest terms 6/9 + 4/9 = 10/9 12/18 + 8/18= 20/18 = 10/9

**ALGEBRA 2 urgent!!**

8x+5y=200 X=length of one rectangle Y=width of one rectangle Area = xy Y= (200-8x)/5 Area=x (200-8x)/5 Hope this gets you going

**college algebra**

Find f(1) and f(2) Find the slope f(1) - f(2) / 1 - 2 Write your equation Rate of change = slope

**Math**

D=4n-1 (1/3)less than (n/d) less than (1/5) (1/3) less than(n/(4n-1)) less than (1/5) Solve the between statement

**Math**

3+(x+y)

**maths**

40(base)=(1/2)(base)(height) 80(base)=(base)(height) Divide by base and they both drop out 80=height

**algebra**

Tan78.2=h/x. h=x(tan78.2) Tan17.6=h/(x+10). h=(x+10)(tan17.6) Need to solve for x and then go back for your height.

**math**

40625/100000 Reduce 40625=5^5 times 13 100000=5^5 times 2^5

**Calculus**

Find the der of f(x) Then substitute 2 into the der of f(x)

**Math**

Q = 11 + D 25Q + 10D = 765

**algebra 2**

Yes you factor 3k(k-5)(k+3) and your check says you did it correctly Now to find the zeros Set each factor = 0. And solve 3k=0. K=0 K-5=0. K=5 K+3=0. K=-3

**8th grade math**

Get a common denominator If you have a/6 and b/6 and c/6, then a:b:c would be the ratio and a+b+c=6

**algebra 2**

Yes (X-7)(x+8) Check by foiling X^2 +8x -7x -56 X^2 +x -56

**algebra 2**

Factor What factors multiply to equal 56 and subtract to equal 1?

**algebra 2**

It does not matter how large your numbers are,just follow the pattern

**algebra 2**

if your zeros are 5and8, then you say: X=5 and x=8 x-5=0 and x-8=0 (X-5)(x-8)=0

**math**

Looks fine to me d/dx sec x = (sec x tan x)(der of x)

**calculus**

I would use 2x as the with and have the radius of the circle be x. Your h would equal (1/2)(52-2x-3.14x) I think the x and h should be closer The closer the numbers, the max the area