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PLEASE HELP ME ASAP!

What is the solution to the system of equations?
1/4x - 1/2y = 8
1/2x + 3/4y = -5

1. (–8, –12)
2. (–8, 12)
3. (8, 12)
4. (8, –12)

1 Answer

2 votes

Answer:

4. (8, -12)

Step: Solve 14x+−12y=8 for x:

14x+−12y=8

14x+−12y+12y=8+12y(Add 1/2y to both sides)

14x=12y+8

14x14=12y+814(Divide both sides by 1/4)

x=2y+32

Step: Substitute 2y+32 for x in 12x+34y=−5:

12x+34y=−5

12(2y+32)+34y=−5

74y+16=−5(Simplify both sides of the equation)

74y+16+−16=−5+−16(Add -16 to both sides)

74y=−21

74y74=−2174(Divide both sides by 7/4)

y=−12

Step: Substitute−12 for y in x=2y+32:

x=2y+32

x=(2)(−12)+32

x=8

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