Question

please help, will give brainlist!

to start solving a system of equations below, which number would you multiply the equation -2x -5y = -1 by

A. 8
B. 2
C. 6
D. 4

Answer 1

Answer:

B. 2

Step-by-step explanation:

This is solving the system of equations by elimination.

Multiply the first equation by 2 and multiply the second equation by 1:

2 (-2x-5y = -1)

1 (4x + 2y = 8)

Becomes:

-4x-10y = -2

4x+2y = 8

Add these equations to eliminate x:

-8y = 6

Then solve -8y = 6 for y:

-8y = 6

-8y/-8 = 6/-8

y = -3/4

Then plug the y back in to solve for x:

−2x−5y = −1

-2x-5(-3/4) = -1

-2x + 15/4 = -1

-2x + 15/4 + -15/4 = -1 + 15/4

-2x = -19/4

-2x/-2 = -19/4 /-2

x = 19/8