Question

i need help solving this
5x -7y=9
4x + 3y =33

Answer 1

you need to get rid of one of the variables... x or y
in this case it doesnt matter which one, what do you want to get rid of?

Answer 2

the y

Answer 3

we need to make it so when we add the two equations together, the y variable will be eliminated.

Answer 4

we can multiply a number times an equation....as long as we multiply that number times everything in the equation.

Answer 5

In this problem, the best way to do that is to
1. multiply the top equation by the coefficient of the bottom y (3)
2. multiply the bottom equation by the coefficent of the top y (7)

it would look like this:
(3) 5x - 7y = 9
(7) 4x + 3y = 33

15x - 21y = 27 notice how now the coeff are the same number
28x + 21 y = 231 but with different signs...when we add them
we get 0y which is 0
43x = 258 now divide both sides by 43 to find x.

once you what x equals, substitute that into
either of the original equations and solve for y

try to finish it on your own