Math CentralQuandaries & Queries


Question from Bob, a student:

solve the system:

x/2 - 2y= -8
3x + 2/3y= -10

Hi Bob.

If you multiply the second equation by 3, you get:
9x + 2y = -30

Now we add the two left-hand-sides and make that equal the sum of the two right-hand-sides:
(x/2 - 2y) + (9x + 2y) = (-8) + (-30)

Can you simplify this and solve for x? Use that value of x to find y.

Hope this helps,
Stephen La Rocque

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