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3 years ago

Solve this system of equations by elimination: 8x+9y=48 12x+5y=21

Mathematics

1 answer:

Olin [163]3 years ago

7 0

Answer:

Let's solve your system of equations by elimination.

8x+9y=48;12x+5y=21

Steps:

Multiply the first equation by 5,and multiply the second equation by -9.

5(8x+9y=48)

−9(12x+5y=21)

Becomes:

40x+45y=240

−108x−45y=−189

Add these equations to eliminate y:

−68x=51

Then solve−68x=51for x:

−68x /−68 = 51 /−68 (Divide both sides by -68)

x= −3 /4

Now that we've found x let's plug it back in to solve for y.

Write down an original equation:

8x+9y=48

Substitute

−3 /4

8x+9y=48:

8( −3 /4 )+9y=48

9y−6=48 (Simplify both sides of the equation)

9y−6+6=48+6 (Add 6 to both sides)

9y=54

9y /9 = 54 /9 (Divide both sides by 9) y=6

Answer: x= −3 /4 and y=6

Hope This Helps! Have A Nice Day!!

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