Posted by Tamir on Wednesday, July 7, 2010 at 9:35pm.
Hello, could someone check my answers to the following
1.For the function f(x) = x^2  2x + 1,
(a) find f(0)
My Ans:
(0) = 0²  2(0) + 1
= 0  0 + 1
= 1
f(0) = 1
(b) solve f(x) = 0
My Ans:
0 = x²  2x + 1
(x  1)(x  1) = 0
(x  1)² = 0
x = 1
2. (Solve and check) The amount of money that a salesperson makes varies directly as the total amount of sales made. If the salesperson receives $7,500 for selling a house for $120,000, how much will he or she make if he or she sells a house for $150,000?
My Ans:
x = commission on $150,000
120,000/ 150,000 = 7500/x
120,000x = 150,000 * 7500
120,000x = 1125000000
x = 1125000000/120,000
x = $9,375 (how do I do the check?)
3. If y varies inversely as x^2, and y = 2 when x = 4, what is the constant of variation?
My Ans:
y = k/x^2
2 = k/4^2
2 = k/16
k = 32
I not very sure with this, especially #3.
Thanks in advance.

Algebra  Reiny, Wednesday, July 7, 2010 at 10:47pm
good job, all answers are correct.
for a check of #2 you could find the rate of commission
7500/120000 = .0625
then .0625(150000) = 9375