Monday
February 8, 2016

Posts by STEVE

Total # Posts: 37,488

algebra
2(a-3) = b+3 a+5 = 2(b-5) A has $11, B has $13
February 2, 2016

Math Help
No diagram, but probably A, if the two form a straight line.
February 2, 2016

chemistry
write the balanced equation, then compare ratio of the number of moles of each.
February 2, 2016

algebra
If the woman is w, and the son is s, then we know w-7 = 4(s-7) w+7 = 2(s+7) woman is 35, son is 14
February 2, 2016

math
doesn't look like one to me. It's an equation.
February 2, 2016

mathematics extension
not sure. What was the question? distance from start? bearing from start to finish? Name of pilot?
February 2, 2016

Math
well, the slope is undefined; the line is vertical. So, the line is x=5 The line y=11 has zero slope. So, the line through (2,-5) is y = -5
February 2, 2016

Maths
y = x(x+4) The roots are at 0 and -4, so the vertex is at -2. see http://www.wolframalpha.com/input/?i=x^2+%2B+4x
February 2, 2016

math-Polya
not sure about Polya, but the maximum-area quadrilateral is a square. as for the circle, since c = 2πr and A = πr^2, A = c^2/(4π)
February 2, 2016

Math
The total points are not 13, but 35+10 = 45. So, using x,y,z for the scoring plays in the same order as described above, 6x+y+3z = 45 x = y x = 6z You certainly don't need elimination for this, since the substitutions are so easy.
February 2, 2016

algebra
since v = Bh, you have 264 = 48h ...
February 1, 2016

Calculus
First off, the equation should be (f(x+h)-f(x-h))/(2h) if f(x) = a(x-b)^2+c, then f(x+h) = a(x-b+h)^2+c f(x-h) = a(x-b-h)^2+c f(x+h)-f(x-h) = a((x-b +h)^2 - (a-b -h)^2 = 4ah(x-b) divide that by 2h and you have 2a(x-b) Now, f'(x) = 2a(x-b) ta-daa
February 1, 2016

Precal
enter your coefficients here: http://www.gregthatcher.com/Mathematics/GaussJordan.aspx
February 1, 2016

math
well, if you got 100% on all your tests, that would account for 70% of your grade. So, you'd then need at least 33.3% on the homework. But, if you scored 100% on all the homework, that would account for 30% of your grade, so you'd need 71.43% on the tests. So, the ...
February 1, 2016

More math
all correct. good work.
February 1, 2016

Math
if there are c chickens, then there are 40-c cows. So, adding up the legs, 2c + 4(40-c) = 100
February 1, 2016

Do I have enough time
Don't forget that you will have to spend a half hour correcting your spelling and grammar, too!
February 1, 2016

Math
If I read your language correctly, there is a 5m border around the field. So, if the dimensions of the whole area is 130x85, then the field is 120x75.
February 1, 2016

Math
as usual, k∘d = k(d) = √(d^2+100) = √((35t)^2+100) assuming t is in hours.
February 1, 2016

math
NO! Read we wrote!!! The sides are 9 over √2
February 1, 2016

math
If the diagonal is d=x√2, then x = d/√2 you did d*√2 instead.
February 1, 2016

Biology
Wine is made by mixing yeast with grapes and allowing the yeast cells to undergo fermentation. Sparkling wine is a type of wine that contains high levels of dissolved carbon dioxide. What is the source of the carbon atoms in the carbon dioxide found in sparkling wine? ethanol ...
February 1, 2016

Biology
I'm sorry I meant c
February 1, 2016

Biology
What would most likely happen to cells placed in fresh water? a- water would flow out because they are hypotonic to the external environment b- water would flow into them because they are hypotonic to the external environment c- water would flow out of them because they are ...
February 1, 2016

math
assuming you want integer values, just find the factors of 389 Hmm. 389 is a prime number. So, just pick any value (x) for the width and the length is 389/x. I suspect a typo.
February 1, 2016

chemistry
HCl + NaHCO3 = NaCl + H2O + CO2
February 1, 2016

Math
That is correct.
February 1, 2016

Geometry
4(1)-4(-1)+2 = 4+4+2 = 10 ??
February 1, 2016

Geometry
I don't see any choices which work. I suspect a typo.
February 1, 2016

Geometry
That does not work: 2(1)-2(-1)+2 = 6 Better try again.
February 1, 2016

Math
seems so.
February 1, 2016

Science
since F = 9.5 N/m, you want W = ∫[0,0.06] 9.5 x dx = 0.0171Nm = 0.0171J see http://www.intmath.com/applications-integration/7-work-variable-force.php
February 1, 2016

Math
it is only one of them.
February 1, 2016

Math
see previous post.
February 1, 2016

Math
yes.
February 1, 2016

Math
yes
February 1, 2016

algebra
just substitute 8 for each of the t's and add up teh numbers.
February 1, 2016

Geometry
The sides are 2x,3x,4x Add them up and you have 9x=45 ...
February 1, 2016

Geometry
The angles are 3x,4x,5x Sum them up and you have 12x=180 Now find x, and thus the angles.
February 1, 2016

Math
Recall that for a cubic polynomial ax^3+bx^2+cx+d, the sum of the roots is -b/a. The sum of the roots is -3-1+5 = 1 So, only A is the answer.
February 1, 2016

Science
looks good to me.
February 1, 2016

Math
Find functions of f•g, g•f, and their domains. f (x)=sqrtx-1, g (x)=x^2 Thank you very much
February 1, 2016

maths
9/2 (2a+8d) = 216 (a+2d)/a = (1+6d)/(a+2d) One choice is 24, 24, 24, ... Probably not what you want. So, let's try 8, 12, 16, ...
February 1, 2016

Pre-Algibra
pi r^2 h = v 3.14 * r^2 * 14 = 718.4 Now just find r.
February 1, 2016

Math
just scramble DEF in the same order as ABC. clearly the 1st and last choices are wrong...
February 1, 2016

math
If Z is the vertex, then the other two angles are (180-25)/2 If Z is one of the base angles, then other is also 25, and the vertex angle is 130
February 1, 2016

math
funny thing -- it looks like every other sine wave... http://www.wolframalpha.com/input/?i=sin%281*pi*1000t%29+%2B2 No idea what v(t) has to do with it, though.
February 1, 2016

Math
you could be right.
February 1, 2016

Math
4 bagels, 5 people 4/5 bagel/person
February 1, 2016

Math
statement: p => q converse: q => p contrapositive: -q => ~p inverse: ~p => ~q
February 1, 2016

Math
that would be true, but alas, 150° is not an acute angle. and that's obtuse, not abuse...
February 1, 2016

Physics
heavy, man...
February 1, 2016

math
your given solutions are correct. As for the last one, x+y=100, so x(100-x)=60 ...
February 1, 2016

math
ad-bc=0 ad = bc a/c = b/d
February 1, 2016

Math
for x ft^2, the cost will be equal when 79.50 + 1.00x = 0.00 + 2.50x
February 1, 2016

Math
you know that √n has domain n>=0. So, your domain is all x such that 7-3x >= 0 And you [should] know that the range of a^u is (0,∞).
January 31, 2016

Physics
looks good, except it should be (100-10)/20
January 31, 2016

Math
1/3 + 5/6 = 2/6 + 5/6 = 7/6 = 1 1/6 No idea what the rest of the stuff is saying.
January 31, 2016

pre-calc college
No idea. What's x? 4 uncut lengths will for a square, the quadrilateral which has the largest area for a given perimeter.
January 31, 2016

Trigonometry
oh, come on. You want QII and QIV. So, using π/4 as a reference angle, that gives you for your first solution, 3π/4 Now the period of cot(x) is π, so add/subtract π over and over till you arrive at -2π or 2π 3π/4+π/4 = 7π/4 3π/...
January 31, 2016

Trigonometry
cot π/4 = 1 now, where is cot(x) negative? Use π/4 as your reference angle.
January 31, 2016

physics
at t=0 we have 12.5 sin(0+x) = -0.0325 x = -0.149 So, x(t) = 12.5 sin(3πt - 0.149) = 12.5 sin(3π(t-0.0159)) So, the phase is -0.0159
January 31, 2016

Math
assuming sunset at 6 pm, the angle of elevation of the sun at 3 pm is 45°, so the shadow is as long as the tree's height.
January 31, 2016

surface area and volume
Hmmm. I interpret the problem to be that the cones have the same diameter. Hence, the same base radius. Since the curved surface area is πrs, if r is constant, then the area is proportional to s, so it is also in the ratio 5:4.
January 31, 2016

math
I have no idea how to read your text. Is x a variable or a multiplication operator? Online we usually use * for multiplication. -- is not an operator I know. You would do well to read some other math postings to see how expressions are written. Yours is gibberish.
January 31, 2016

math
why not use real math? (x-6)/3 - (x-27)/9 = 3 x=9 or, since you are careless with parentheses, (x-6)/(3-x) - 27/9 = 3 x = 24/7 I suspect the first one was your intention. Use parentheses to make things clear. And lose all those useless words! This is math!
January 31, 2016

Math
Assuming you want 384 pieces, each is 1 inch long. Now take a hike.
January 31, 2016

Math
don't hold your breath. Until you say how many parts you want, there's no way to determine how long each must be. Consider the factors of 32. Pick one.
January 31, 2016

Algebra
since time=distance/speed, 40/(20-x) = 60/(20+x)
January 31, 2016

math
any number greater than 1 will work 1/5 < 2/7 < 1/3 1/5 < 9/35 < 1/3
January 31, 2016

Math
If the fast pump takes x hours, then 1/x + 1/(4x) = 1/4 Solve for x, and then use 4x as your time.
January 31, 2016

math
There are several useful formulas, though, such as a^2-b^2 = (a+b)(a-b) You have 16-36p^2 = 4^2-(6p)^2 = (4+6p)(4-6p) = 4(2+3p)(2-3p)
January 31, 2016

math
This kind of thing just takes practice. You know the factors will look like one of (12x-?)(x-?) (6x-?)(2x-?) (4x-?)(3x-?) where the two ? numbers are 1 and 5. Then it's just trial and error. Eventually you will wind up with 12x^2-23x+5 (4x-1)(3x-5)
January 31, 2016

Math
well, just use the given numbers. The ratio is 9.6/22.2 Now you can turn that into a simplified fraction by multiplying top and bottom by 10, the canceling common factors.
January 31, 2016

Algebra
Draw a diagram. That simple step will make solution a lot easier. A(x) = (20+2x)(15+2x) Now you can expand that to standard form.
January 31, 2016

engineering
well, uh, g, plug in the numbers! 20 miles = 32.2 km, so A(32.2) = 9.81(6380/(6380+32.2))^2 = 9.71 m/s^2
January 31, 2016

Calculus
f(-2) = (-2)^4 = 16 f'(x) = 4x^3, so f'(-2) = 4(-2)^3 = -32
January 31, 2016

calculus
x(2x)(z) = 36000 so, the height z is 18000/x^2 the area is 4x^2 + 2xz + 4xz the cost in centavos is c = 10*4x^2 + 5*2xz + 5*4xz = 40x^2 + 30xz = 40x^2 +540000/x = 40(x^2 + 13500/x) minimum cost is when dc/dx=0 dc/dx = 40(2x-13500/x^2) = 80(x^3-6750)/x^2 dc/dx=0 when x^3 = 6750...
January 31, 2016

Math Algelbra
since time = distance/speed, then the time for walk = 10/4 bike = 10/10 car = 10/40
January 31, 2016

Physics
you know the height y is y(t) = 1.5 + 30*.866t - 4.9t^2 = 1.5 + 25.98t - 4.9t^2 y(4) = 27.02 max height is y(2.65) = 35.94 vertical speed is 25.98-9.8*4 = -13.22 horizontal speed is 15.00 So, speed at impact is 20.00 m/s
January 31, 2016

Calculus and Vectors
see related questions below
January 31, 2016

Maths
well, just plug in the numbers! 1/3 * 24^2 * 30 = ?
January 31, 2016

Calculus Plz Help
see later repeat posting.
January 31, 2016

Geometry
the topic is discussed quite well at http://jwilson.coe.uga.edu/emt668/emat6680.folders/brooks/6690stuff/righttriangle/rightday3.html
January 31, 2016

Geometry
Thank you
January 31, 2016

Geometry
Draw a diagram. The answer is clearly (4)
January 31, 2016

Geometry
Which of the following represents the length of a diagonal of a trapezoid with vertices of (-b,c), (b,c), (-a,0), and (a,0)? 1- sq root (a+b)^2-c^2 2- sq root (a-b)^2 - c^2 3- sq root (a-b)^2 +c^2 4- sq root (a+b)^2 +c^2
January 31, 2016

Maths
3x-12 = (2/3)x + 16 now just solve for x.
January 31, 2016

maths
The way it is given, I expect the general rule is Tn = 4n-1
January 31, 2016

pre-cal
42
January 31, 2016

QMB
1st groups scores were more spread out, but generally scored higher.
January 31, 2016

algebra
Can't tell. I need to know the expected value of the mix, somewhere between $3 and $5 per lb. If its cost is to be $n/lb, then 5x + 3*10 = n(x+10)
January 31, 2016

caculas
see related questions below
January 31, 2016

mathematics
If you mean (6 to the power 5) ÷ (6³) + (7 to the power zero) or, losing all the static 6^5 / 6^3 + 7^0 = 6^2 + 1 = 37 You may group otherwise, but the evaluations of the powers will be the same.
January 31, 2016

Matrix question
yes. (AB)t = (Bt)(At) works like inverses.
January 31, 2016

math
well, 65=5*13 now you know the length and width, so ...
January 31, 2016

Matrix
(AB)t = (Bt)(At)
January 31, 2016

Math
right arm.
January 30, 2016

Math
the hypothesis is what you are not sure of. It is almost always preceded by "if." So, A
January 30, 2016

calculus
well, just set demand = supply and solve for p.
January 30, 2016

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