SLA Rockets.........Class of 2010
Showing posts with label Substitution Method. Show all posts
Showing posts with label Substitution Method. Show all posts

Sunday, December 16, 2007

Substitution Method

FX-50

y=-x-2 and 5x-3y=22

5x-3(-x-2)=22
5x+3x+6=22
8x+6=22
8x=16
x=2

y=-(2)-2
y=-2-2
y=-4

x=2 and y=-4

You have a system of equations, y=-x-2 and 5x+3y=22. One of them looks easier to solve than the other, so first substitute the easier equation into the harder one and simplify. Once you do that, you should have the equation 5x+3x+6=22. Now, go ahead and solve for x. You found that x=2, so substitute 2 for x in the first equation and you can solve for y. You should get y=-4. So x=2 and y=-4. Now you have solved the system of equations.