Math Help Please?

Question

1. If p varies inversely with q, and p = 10 when q = 1/2, what is the value of p when q = 20?


A.Option 1: 1/4
B.Option 2: p = 1
C.Option 3: p = 5
D.Option 4: p = 400

2. (x/x+2) = x/3 - 2/x+2
A. {-2,3}, x =/ -2
B. {3}, x =/ -2
C. {-3}, x =/ -2
D. {-2}, x =/ -2

Answer 1

p=kq
10=(1/2)k
k=20

p=20q
p=20(20)
p=400

therefore D

(x/x+2) = x/3 - 2/x+2
x/(x+2) = (x^2+2x-6)/(3x+6)
3x^2+6x=x^3+2x^2-6x+2x^2+4x-12
x^3+x^2-8x-12=0

therefore x = 3 or x = -2

therefore B

Answer 2

B. for Q 2

Answer 3

A. 1/4.

P = 5/Q so when P=10, then Q=1/2. When Q=20, P=5/20 or 1/4.

I can't answer #2 without better notation.

Answer 4

p is of the form p=k/q replace p=10 q=1/2 you find k=5

p=5/q if q=20 p =5/20 =1/4 Answer A

put the fraction on a common denominator 3(x+2)

3x/3(x+2) =x(x+2)/3(x+2) -6/3(x+2)
multiply by 3(x+2)

3x = x^2+2x-6 or x^2-x-6 =0
the result is 3 the other root x=-2can not be used since x+2 =0

Answer 5

#1 the answer is D. What you do is put P over Q which is 10 over 1/2. You equal that to P over 20. From there you cross multiply which you multiply 10 times 20 then divide by 1/2.

I dont know anything about #2 but I hope that helps you with #1.

Answer 6

1.this is simple. so q=1/2 for the 1/2 to become 20 you have to multiply it 40 times so 10 times 40=400 so it is D

2. number 2 i think it is A

Answer 7

if p varies inversely with q..
then p*q=constant

case 1 p*q=5(10*1/2)

so if q is 20 then p is 1/4 so that 5 is their product........

b is confusin....