Question

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

Answer 1

Answer:

D. (–3, –6) and (5, 10)

Step-by-step explanation:

The system has equations:

$y=2x$...(1)

and

$y=x^2-15$...(2)

Equate both equations;

$x^2-15=2x$

Rewrite in standard form:

$x^2-2x-15=0$

We factor to obtain:

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

By the zero product principle;

$(x+3)=0,(x-5)=0$

$\implies x=-3,x=5$

When x=-3, y=2(-3)=-6

This yields the ordered pair (-3,-6).

When x=5, y=2(5)=10

This yields the ordered pair (5,10).

The correct choice is D.