Friday

September 30, 2016
Total # Posts: 44,265

**Maths**

recall that dy/dt = dy/dx * dx/dt You have dx/dt = 0.3 so, plug in x=0 dy/dt = (2 - 8/√4) * 0.3 = -0.6

*September 10, 2016*

**Maths**

what are the factors of 108? 1 108 2 54 3 36 4 27 6 18 9 12 So, how can those be used to add up to 30? (Remember that one has to be used twice)

*September 10, 2016*

**Intro to Algebra**

750,000 - 60,000 = 690,000 2017-1977 = 30 years 690,000/30 = 23,000 V(t) = initial amount + amount increased each year •t Answer: V (t)=60,000+23,000t

*September 10, 2016*

**Science**

ok now what?

*September 10, 2016*

**Math 201**

surely you can see that each ticket costs $5

*September 10, 2016*

**math or chemistry**

Hmmm. I get 106.65 x 10^-8 But, you want that in scientific notation, so it is written as 1.0665 x 10^-6 And, considering the number of significant figures, it would probably be better as 1.1 x 10^-6

*September 10, 2016*

**Math 201H**

it looks like each payment was 400 that should help. The balance starts at 14000 and goes down

*September 10, 2016*

**chemnad school computer application**

sum=0 for n=101 to 199 step 2 { sum += n } or, by hand, pair them up: 101 + 199 = 300 103 + 197 = 300 ... how many such pairs are there? Or, since the sum of the 1st n odd numbers is n^2, 100^2 - 50^2 = 7500

*September 10, 2016*

**Math**

j = 3g j = 4b g = 8 Now just find b: j = 3*8 = 24 24 = 4b b = 6

*September 9, 2016*

**physics**

75 mi/hr * 1609m/mi * 1hr/3600s * 3s = (75*1609*3)/3600 m

*September 9, 2016*

**Math**

140 = 2^2 * 5 * 7 168 = 2^3 * 3 * 7 210 = 2 * 3 * 5 * 7 So, what is the biggest number that divides all of those?

*September 9, 2016*

**Physics**

distance: s = 1/2 at^2 speed: v = at

*September 9, 2016*

**Physics**

time rising: 4.9t^2 = 1.29 double that for total hang time. v = 9.8t

*September 9, 2016*

**Math**

can't see the diagram, but just add up the distances. How hard is that?

*September 9, 2016*

**Physics**

4.9t^2 = 370 v = 9.8t

*September 9, 2016*

**math**

well, there are 4 sides, so ...

*September 9, 2016*

**Math**

since the other wall is also 20 ft, and area = length * width, it is 20ft * 20ft = 400 ft^2

*September 9, 2016*

**Algebra**

2^-1 + 4^-5 = 1/2^1 + 1/4^5 = 1/2 + 1/1024 = 513/1024 You can always type in your expressions at wolframalpha.com to verify your answers

*September 9, 2016*

**Math**

read the question again carefully. Only boys or girls in each row. Why did you combine them into rows of 18?

*September 9, 2016*

**Math**

consider that 9 divides both 72 and 90

*September 9, 2016*

**Physics**

F = ma, so together, (6.0+4.0) = 3.2a opposite, (6.0-4.0) = 3.2a

*September 9, 2016*

**Physics**

F = ma, so 0.40a = 25

*September 9, 2016*

**Grammar world**

subject, verb, dir obj, obj complement they | crowned | him / king

*September 9, 2016*

**Algebra**

Hmm. Watch those minus signs. (x^-2)^3 (x^2)^4 = x^-6 * x^8 = x^2 x^2/x^15 = 1/x^13 = x^-13

*September 9, 2016*

**Math**

15 m/s * 1km/1000m * 3600s/hr = 15*3600/1000 km/hr 750m * 1s/15m = 750/15 s

*September 9, 2016*

**math**

The difference in meaning is that -3 is a signed value. It lies to the left of zero +3 is also a signed value, and since it is positive, it lies to the right of zero |-3| is just the physical distance (left or right) of -3 from zero. Since we live in a physical world, all ...

*September 9, 2016*

**Math Help needed quickly**

Think on it. If there were 55 ml alcohol, there would be 45 ml water. That's 10 ml less. We have 20 ml less, so there must be 110 ml alcohol 90 ml water

*September 9, 2016*

**Math - hmmm**

I'm not familiar with this notation. Have you some other information, maybe a subject topic in your text?

*September 9, 2016*

**Math**

just add up the amount of work done by A and B in a minute. Together, they do 1/20 of the job: 1/36 + 1/x = 1/20

*September 9, 2016*

**Math**

I think that's draughts, not droughts! Just my dry wit...

*September 9, 2016*

**Calculus**

so it does. It's just Algebra I to figure it out. What do you get?

*September 9, 2016*

**calculo**

f = 4x^(5/4) + 10x^(3/2) f' = 4(5/4)x^(1/4) + 10(3/2)x^(1/2) = 5∜x + 15√x f'(4) = 5∜4 + 15√4 = 5√2 + 30

*September 9, 2016*

**Math**

4Q-8 = 3 4Q = 11 Q = 11/4

*September 9, 2016*

**mates**

20+65 = 85 + 76 = 161

*September 9, 2016*

**Math**

Using 15% of 27.60 is wrong, because the 27.60 already includes the tip. Instead, you should use 3p * 1.15 = 27.60

*September 9, 2016*

**Math**

you know that the whole circumference is 2πr. You have only a fraction of that; namely, 110/360 * 2πr

*September 9, 2016*

**Calculus**

dT/dt = -.0065 dh/dt so plug in you number for dh/dt

*September 9, 2016*

**Algebra 2**

must be right then.

*September 9, 2016*

**ALGEBRA 2**

no problem. Guess all you had to do was think about it a bit.

*September 9, 2016*

**Math**

(1/2)/2 + 1

*September 9, 2016*

**math**

That is correct. They have to satisfy the Cauchy-Riemann equations.

*September 9, 2016*

**Math.**

you're kidding, right? with google and online dictionaries at your fingertips, you post such a question?

*September 9, 2016*

**anal.gom.**

oops. I botched it a bit, and lost the 3. We pick it up here: (x+8)^2 + 3(y - 50/3)^2 = 2680/3 now get rid of that pesky 3: (x+8)^2/3 + (y-50/3)^2 = 2680/9

*September 9, 2016*

**anal. geom.**

try completing the squares: x^2+16x + 3y^2-100y = -4 x^2+16x+64 + 3(y^2 - 100/3y + (50/3)^2) = -4 + 64 + 3*(50/3)^2 (x+8)^2 + (y - 50/3)^2 = 2680/3 unusual, but hey, it's just numbers, right? But still, it's so odd that I suspect a typo. You sure it's not 4y^2? If ...

*September 9, 2016*

**help please?!**

well, it went down 1/2 M in 1/2 minute.

*September 9, 2016*

**Chemistry**

I think you need to recall that 1 mole of any gas occupies 22.4L at STP.

*September 9, 2016*

**maths**

why don't you make a nice table out of all this stuff and work up some Venn diagrams and maybe show some work and let us know just what the trouble is instead of just tossing a bunch of numbers and stuff into the vat and stirring it up into one long and confusing run-n-and...

*September 9, 2016*

**English**

#2 is more commonly sung, as it reflects the folksy hillbilly type of feel of the song. I have never heard #1 used. Ever. As for the meaning, #1 Nope. #2 maybe, in the sense that the singer is on a trip, coming from Alabama. #3 an ungrammatical rendering of "I have come&...

*September 9, 2016*

**Math.**

rd 45: 45 3*15 wraps: 15 more 3*5 wraps: 5 more 3*1 + 2 wraps: 1 more 1+2 wraps: 1 more

*September 9, 2016*

**Maths**

j = d-3 d+4 = (3/2)(j+4) plug in j and solve for d.

*September 9, 2016*

**Math**

well, x(x+7) is a multiple of 60. 5*12 = 60 guess that works, eh?

*September 9, 2016*

**Physics**

the speed drops from v to zero when the ball reaches max height. since the speed is v - 9.8t that is zero when t=3, so v - 9.8*3 = 0 ... then, you know that the height is vt - 4.9t^2 Now you know v, and t=3, so plug and chug.

*September 9, 2016*

**MATH TRIGONOMETRY**

Tell you what. I'll do the graph, and you answer the questions. http://www.wolframalpha.com/input/?i=-x(x-1)(x%2B2)

*September 8, 2016*

**Algebra 2**

if a lbs are type a, then the rest (600-a) are type b. So, add up the parts and make sure it matches the whole: 75a + 52(600-a) = 60*600

*September 8, 2016*

**Physics**

a = 42m/s / 2s = 21m/s^2 s = 1/2 at^2

*September 8, 2016*

**Math**

5(14+10) = ?

*September 8, 2016*

**Math**

Not D, because f(3) has two different values. So, f is not a function.

*September 8, 2016*

**Math**

next steps: 8(7-27)/8 + 245 8(-20)/8 + 245 ...

*September 8, 2016*

**Math**

as long as each x value appears only once, it is probably a function. So, I'd pick A and B on that basis. D also works. While 0 appears twice as the first element, the 2nd element is the same. So, the pair (0,3) appears twice, but it does not violate the rules for functions.

*September 8, 2016*

**Math**

8 + 6/2 = 11

*September 8, 2016*

**math**

v = at so, how long does it take to fall 685 ft?

*September 8, 2016*

**Math**

not sure what each watermelon with 12.73 inches and 2.7 inches in height means

*September 8, 2016*

**Algebra**

3*84 <= 81+87+x <= 3*89 254 <= 168+x <= 267 ...

*September 8, 2016*

**Algebra**

since distance = speed * time, 20x = (20-4)x + 6 and I think you meant "downwind"

*September 8, 2016*

**Math**

correct. If you type in your expressions at wolframalpha.com you can check your answers quickly. For example, http://www.wolframalpha.com/input/?i=2+1%2F7+divided+by+3+2%2F3

*September 8, 2016*

**math**

That's h of x, not h times x. h(x) = √(4-x^2)/(x-3) or h(x) = √((4-x^2)/(x-3)) In either case, x=3 is excluded because the denominator is zero. Now, √z has a domain of z>=0. In the first case, 4-x^2 >= 0, so x^2 <= 4 |x| <= 2 In the second ...

*September 8, 2016*

**Maths**

roughly 0.6 * 150

*September 8, 2016*

**Algebra 2**

15000/3500 = ? round up to next whole bucket

*September 8, 2016*

**Technology**

correct

*September 8, 2016*

**Math**

just write down the parts and add them up

*September 8, 2016*

**Algebra**

well, 7^2 = 49 8^2 = 64 So, it's either 7 or 8, but now you gotta figure which one.

*September 8, 2016*

**Math**

oh, well, 1 3/7 = 1+3/7 = 7/7 + 3/7 = 10/7

*September 8, 2016*

**Math**

well, the idea is right, but 3/7 = 15/35 Then, do just what you did with the previous problem: 15/35 - 38/35 = -23/35 Plus, you misspelled "to"

*September 8, 2016*

**math**

yes.

*September 8, 2016*

**math**

huh? This is exactly like the last one; just use different numbers. What do you get?

*September 8, 2016*

**math**

c = t+60 t = 2/3 c or, t = 2/3 (t+60)

*September 8, 2016*

**Math**

hey, it's nice to see a problem posted that shows some thought and effort.

*September 8, 2016*

**Math**

for sphere, v = 4π/3 r^3 for cylinder, v = πr^2h so, since the radius of the cylinder is 1, 4π/3 (1^3+2^3) = πh

*September 8, 2016*

**Math**

draw a diagram. The diagonal of the square is the diameter of the circle. Knowing that, you can figure the area of the square.

*September 8, 2016*

**science**

#1 Really, lattices are found in crystals. (Plus, why would that be affected by a charged balloon?) #2 C looks good to me.

*September 8, 2016*

**Math**

google is your friend. just search for equilateral triangle. If the side is s, then perimeter = 3s area = √3/4 s^2

*September 8, 2016*

**Mathematics**

(3 5/7)x = 3 1/4 (26/7)x = 13/4 x = 13/4 * 7/26 = 13/26 * 7/4 = 1/2 * 7/4 = 7/8

*September 8, 2016*

**Math**

total points for 4 tests @ 96 = 384 points so far: 94+98+98 so, how many does he need on the last exam? Hint: 96 is the average of 94 and 98

*September 8, 2016*

**Science**

a magnet will get the iron oil floats on water evaporate the water to get salt

*September 8, 2016*

**physics**

The larger car is the Mercedes-Benz.

*September 8, 2016*

**Maths**

Drop altitudes from C and D. That will create a rectangle and two right triangles. I'm sure you can find those areas. Don't forget the Pythagorean Theorem to find the altitude.

*September 8, 2016*

**Algebra2**

Draw the lines y = 4x-1 y = 3x-1 Shade everything below the 1st, and above the 2nd. The intersection of the two shaded areas is the solution set

*September 8, 2016*

**Algebra2**

Solve the inequalities by graphing y<=4x-1 y>3x-1

*September 8, 2016*

**Math**

2/3 X 21 2 x 7 14

*September 8, 2016*

**AAHHOOOOGAH! Homework Dump!**

how about showing some of your ideas on any one of the problems?

*September 8, 2016*

**Math**

how can a rectangle have three such ratios? If 3:4, then the width is 3x and the length is 4x, and we have 2(3x+4x) = 70

*September 8, 2016*

**Calculus**

Riemann sums, trapezoidal method. google numerical integration or quadrature

*September 8, 2016*

**Calculus**

I don't see any way, other than numerical approximations. The velocity is not a nice linear function, so only an integral can give an exact answer ∫[0,14] (11+6cosx) dx

*September 8, 2016*

**MATHS**

dC/dx = 600 - 180000/x^2 plug in x=100 I assume C(x) is the income function

*September 8, 2016*

**math**

ummm, 33*41 ?

*September 7, 2016*

**Math**

You have the right idea re add 6.75 + 3.5 = 10.25 not 10.35 you have the right process to get per hr $92.25/10.25 =$9 per hr

*September 7, 2016*

**Pre algebra**

a rational number is what you know as a fraction. It is the ratio of two whole numbers. 3/4, -7/11, etc. An integer is a rational number with a denominator of 1. Or, more commonly just what you think of as a counting number, but may be negative: 3/1 = 3 -2/1 = -2 and so on An ...

*September 7, 2016*

**math**

(1/20000)^2 * 50 km^2

*September 7, 2016*

**Math**

You have 8 3.4 gal of paint you're going to use 2/5 of it to paint what type of math would you use to figure how much? Multiplication!! 8 3/4 times 2/5 = see if you can get it from there

*September 7, 2016*