math
posted by Taylor .
solve the system by the elimination method: 4x=5y+24
5x=4y+21

To solve by elimination, you need x and y on the same side of the equation.
For the first one, subtract 5y from both sides to get 4x  5y = 24
For the second one, subtract 4y from both sides to get 5x  4y = 21
You want to add these two equations to eliminate one variable. You have to do something to each equation before this can happen. Multiply the top equation by 5 and the bottom equation by 4. Be sure to multiply each term including the 24 and 21 by those numbers.
When you add, the x's will cancel out and you can solve for y. Once you find the value for y, substitute it back into one of the ORIGINAL equations to find x. Then be sure to check x and y in both of the original equations to make sure, you haven't made a mistake.