A student is trying to solve the system of two equations given below:

Third option

Step-by-step explanation:

We need to either divide the second equation by 3 or -3 to get y or -y, where we would then subtract or add both equations OR multiply the first equation by 3 or -3 to get 3y or -3y, where we would then subtract or add both equations.

The only option that does this is the third.

Hope this helps!

answer: .75 km

step-by-step explanation:

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15