Question 137499: Solve by the substitution method.
4x+7y = 34
-3x+y = 12
Can someone please HELP me with this problem. I do not understand it at all!! Found 2 solutions by checkley77, vleith:Answer by checkley77(12844) (Show Source):
You can put this solution on YOUR website! -3x+y=12 or y=3x+12
4x+7(3x+12)=34
4x+21x+84=34
25x=34-84
25x=-50
x=-50/25
x=-2 answer.
4*-2+7y=34
-8+7y=34
7y=34+8
7y=42
y=42/7
y=6 answer.
proof:
-3*-2+6=12
6+6=12
12=12
You can put this solution on YOUR website! Given: and
Solve using substitution. You have 2 equations and two unknowns, so you can solve this.
When using substitution to solve equations like these, you use the following steps:
1) Use the first equation to find one of the variables in terms of the other variable. We will use and find y in terms of x.
2) Use the value found in step 1 for y as input to the second equation. Once you substitute the value for y from step 1 into equation 2, you have an a single equation with a single variable.
3) Now solve for the variable x
4) Using the value from step 3 for x, substitute back into any of the original equation or the equation from step 1, to solve for y. Just pick one equation that seems easiest to use.
5) Check your answer. Use the two values you've found for x and y in the 'other' original equation to verify. which is true.
So the answer is (-2,6)
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