Solve by substitute:

1) y=2x-1
2x+2y=22

Solove by emlimination:

1) 5x+4y=-83
3x-3y=-12

Solve using a method of your choice:

1) x+2y=23
5x+10y=55

2) y=x+1
2x-2y=-2

Please help me I don't understand any of this, it's my second day of school and I already feel like a failure and im on the verge of crying

5 answers

when it says substitution, use the value from one equation to solve the other.

y = 2x-1, so the 2nd equation becomes

2x+2(2x-1) = 22
2x + 4x - 2 = 22
6x = 24
x = 4

Using elimination, find ways to make one variable disappear by adding the two equations (or multiples of them)

5x+4y=-83
3x-3y=-12

to get rid of y, multiply the two equations by 3 and 4, and you have

15x+12y = -249
12x-12y = -48

Now add them up, and y is eliminated:

27x = -297
x = -11

Now use that value in either of the original equations to get y:

3x-3y = -12
3(-11)-3y = -12
-33 - 3y = -12
-3y = 21
y = -7

Surely your text has examples of this. If not, google will produce lots of examples and explanations online.

working with formulas

-x+y=-13 and 3x-y=19

-x+y=-13 and 3x-y=19 solve by substitute

Sol

ve by substitude