SOLUTION: 7x + 5y =77 3x- 4y = -10

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Question 744227: 7x + 5y =77
3x- 4y = -10
Answer by Chipmonkcheeks(3) About Me  (Show Source):
You can put this solution on YOUR website!
Call 7x + 5y = 77 equation I, and called 3x - 4y = -10 equation II.
Then from equation I, if you -5y from both sides of the equation:
7x+=+77+-+5y ,
Then dividing both sides by 7:
x+=+11+-+%285%2F7%29y .
We can then substitute this expression for x into equation II. This gives us:
3%2811+-+%285%2F7%29y%29+-+4y+=+-10 .
Expanding the brackets:
33+-+%2815%2F7%29y+-+4y+=+-10, which is equivalent to,
43+=+%2843%2F7%29y, which gives us that
y+=+7.
Then substituting this back into our expression for x gives us:
x+=+11+-+%285%2F7%29%2A7,
which give us that
x+=+6
Best to check these answers by substituting them back into the original equations.