To eliminate the y-terms and solve for x in the fewest steps, by which constants should the equations be multiplied by before adding the equations together? First Equation: 5x - 4y = 28 Second equation: 3x - 9y = 30

use - 9 to multiply the first equation

use - 4 to multiply the second equation.

Step-by-step explanation:

5x-4y=28 ... eqn (1) * -9

3x-9y=30 ... eqn (2) * -4

-45x+36y=-252

- (-12x+36y=-120)

therefore, - 33x:33 = -132:-33

x=4.

substitute (x=4) in any of the equation. I'm just going to use eqn 1.

5x-4y=28

5 (4) - 4y=28

20-4y=28

-4y = 28-20

-4y:-4 = 8:-4

y=-2

so, x=4, y=-2

Note: for proof of answers substitute the answers for x and y and see if you have the same result ... e. g

5 (4) - 4 (-2) = 28.