Question 490758
Start off by solving for x in the second equation to go from {{{x+2y=0}}} to {{{x=-2y}}}



Now go back to the first equation and replace each copy of x with -2y (this is legal since x = -2y)



So the first equation goes from {{{2x+2y=41}}} and becomes {{{2(-2y)+2y=41}}}



This is why this method is known as the substitution method. In that last step, I <u>substituted</u> x for -2y. Doing this got rid of one variable so you can solve for the other.



So at this point, you have a linear equation with one variable (y). Solve this equation to find the value of y. Once you have y, use that to find x. You do this by plugging it into {{{x=-2y}}} and evaluating.