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Plz help me how would you solve 4x + 2y = 18, 3x - 5y =20 by elemination

User Paltoquet
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1 Answer

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Answer: x = 5, y = -1

Explanation:

Equation 1: 4x + 2y = 18

Equation 2: 3x - 5y = 20

In order to eliminate one of the variables , find the LCM of either x or y.

I chose to eliminate y. The LCM of 2 & 5 is 10.

Multiply the entire equation so the coefficient of the variable equals the LCM.

Then add the equations and solve for the remaining variable.

5(4x + 2y = 18) --> 20x + 10y = 90

2(3x - 5y = 20) --> 6x - 10y = 40

26x = 130

÷26 ÷26

x = 5

Next, input x = 5 into either of the equations to solve for y.

Equation 1: 4x + 2y = 18

4(5) + 2y = 18

20 + 2y = 18

-20 -20

2y = -2

÷2 ÷2

y = -1

User Gomino
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