Q:

7x+8y=10 5x+y=−7 solve by elimination

Accepted Solution

A:
Answer:(-2,3)Step-by-step explanation:7x+8y=105x+y=-7To solve this by elimination, we need both equations in the same form.  There are.  They are both in form ax+by=c.Now we also need for one of the columns with the variables to be opposite or same terms.I like the way the column with the y's are looking because if I multiply that second y by 8 or -8 I will have sames or opposites.I'm going to multiply the second equation by -8.This will give me:   7x+8y=10-40x-8y=56--------------------Add the equations! -33x+0=66  -33x   =66       x    =66/-33        x  =-2Now we need to find the other variable. It doesn't matter which equation you use.I'm going to use 5x+y=-7 where x=-2 to find y.5(-2)+y=-7-10+y=-7Add 10 on both sides      y=3The solution is (-2,3)