SOLUTION: Please help me solve the system of equation by the substitution method: {{{3a-b=7 and 2a+2b=5}}}

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Question 811768: Please help me solve the system of equation by the substitution method: 3a-b=7+and+2a%2B2b=5
Found 2 solutions by josgarithmetic, MathTherapy:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Multiply the first equation by 2, and then add the left members of both equations, add the right-hand members of both equations, and equate these two sums. Solve directly for the variable, a. Use this result to find the value of variable b.

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!

Please help me solve the system of equation by the substitution method: 3a-b=7+and+2a%2B2b=5

3a - b = 7________b = 3a - 7 ------ eq (i)

2a + 2b = 5 ----- eq (ii)

Substitute 3a - 7 for b in eq (ii), and then solve for a

Substitute value for a in any of the 2 equations to determine the value of b

Then do a check!!

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