Question

HELP PLEASE !!!! Rosana used linear combination to solve the system of equations shown. She did so by multiplying the second equation by a certain number to eliminate the y-terms. What number did Rosana multiply the second equation by?

x - y= 15
0.5x + 0.2y = 25

Answer 1

She must have multiplied it by 5.

That would've given her:

x - y = 15

2.5x + y = 25

Now we can add them and the y-terms will eliminate each other. Because one is -y, and the other is positive y. -y + y = 0

Answer 2

She must have multiplied it by 5.

That would've given her:

x - y = 15
2.5x + y = 25

Now we can add them and the y-terms will eliminate each other. Because one is -y, and the other is positive y. -y + y = 0.