# Pre-Calculus

posted by .

Use substitution method to solve.

(1/2x)+(3/4y)=(-1/4) and (3/4x)-(1/4y)=1

• Pre-Calculus -

first, I'd get rid of those pesky fractions:

2x + 3y = -1
3x - y = 4

Now you can see that y = 3x-4, so substitute that back in the 1st equation:

2x + 3(3x-4) = -1
2x+9x-12 = -1
11x = 11
x = 1
so, y=3x-4 = -1

be sure to check that the answer fits the original equations.

• Pre-Calculus -

Thank you.

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