how to solve using elimination method,no solutation or infinate?

4x-8y=48

11x+3y=105.5
in Algebra 1 Answers by Level 3 User (2.2k points)

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1 Answer

Problem: desperate for help, how to solve
how to solve using elimination method,no solutation or infinate?
4x-8y=48
11x+3y=105.5

To eliminate one of the variables, we need the co-efficients to have
the same absolute value, so we can either add the equations or subtract
the equations.

1) 4x - 8y = 48
2) 11x + 3y = 105.5

Let's eliminate the y term. Multiply equation 1 by 3, and multiply
equation 2 by 8.

3(4x - 8y) = 48 * 3
3) 12x - 24y = 144

8(11x + 3y) = 105.5 * 8
4) 88x + 24y = 844

Add equation 4 to equation 3.

   12x -  24y = 144
+(88x + 24y = 844)
-------------------------
 100x           = 988
100x = 988
x = 9.88

Plug that into equation 1 to solve for y.

4x - 8y = 48
4(9.88) - 8y = 48
39.52 - 8y = 48
-8y = 8.48
y = -1.06

Plug both of those values into equation 2 to check them.

11x + 3y = 105.5
11(9.88) + 3(-1.06) = 105.5
108.68 - 3.18 = 105.5
105.5 = 105.5

Answer: x = 9.88, y = -1.06

 

by Level 11 User (78.4k points)

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