2x because its 2 times the price of the book (x)
Answer:
B.
Step-by-step explanation:
That would be y = (x +10)^2.
Answer:
See below
Step-by-step explanation:
x^2-3x-40 Factor
(x - 8) (x + 5)
The x intercepts are -5 and 8
(negative infinity, -5)
(8, positive infinity)
Answer:
a) 
b)
when 
Step-by-step explanation:
since y varies inversely with x.
We need to find the constant, k.
Let's use a point (x,y) on the curve.
We are given an (x,y)=(5,10):
Multiply both sides by 5:

.
So the equation is:

What is y when x=2?


Answer:
9x^4+3x^2 -6
Step-by-step explanation:
(3x^2-2)(3x^2+3)
expand to remove the bracket
9x^4 + 9x^2 -6x^2 - 6
9x^4 + 3x^2- 6