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)

Question

asked Apr 14, 2020 45.0k views

2 Answers

Fhl · Answer 1 · 2020-04-19T02:03:04+0000

Answer:

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.