Question

Solve the system of equations. y = 2x y = x 2 – 15

A. (–3, –6) and (–5, –10)

B. (3, 6) and (–5, –10)

C. (3, 6) and (5, 10)

D. (–3, –6) and (5, 10)

Answer 1

d is your answer

Explanation:

Answer 2

Option D.

Explanation:

The given system of equations is

`y=2x` ....(i)

`y=x^2-15` ...(ii)

From (i) and (ii) we get

`x^2-15=2x`

`x^2-2x-15=0`

`x^2-5x+3x-15=0`

`x(x-5)+3(x-5)=0`

`(x-5)(x+3)=0`

Using zero produc property we get

`x-5=0\Rightarrow x=5`

`x+3=0\Rightarrow x=-3`

If x=5, then

`y=2(5)=10`

If x=-3, then

`y=2(-3)=-6`

The solutions of the given system of equations are (-3,-6) and (5,10).

Therefore, the correct option is D.