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(PLEASE HELP, DUE BY TONIGHT!)

Use linear combination to solve the system of equations. Show your work. Check your answer to show proof that the solution works in each equation.
2x+4y=6
x-4y=-21
(If possible, please put a step by step explanation for both y and x axis!!)

User Atheaos
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1 Answer

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Start with the first equation: 2x + 4y = 6
Multiply the first equation by -1 to create a second equation with the same leading coefficient for y: -2x - 4y = -6
Add the two equations together: 0x + 0y = 0
The y terms cancel out and we are left with: 0x = 0, so x = 0.
Substitute x = 0 into either equation to solve for y:
Using the first equation: 2x + 4y = 6 becomes 2(0) + 4y = 6, so y = -3/2
Using the second equation: x - 4y = -21 becomes 0 - 4y = -21, so y = 21/4
The solution to the system of equations is (x, y) = (0, -3/2) or (0, 21/4).

To check the solution, we can substitute the values of x and y back into the original equations and see if the solution satisfies both:

First equation: 2x + 4y = 6 becomes 2(0) + 4(-3/2) = 6, which is true.
Second equation: x - 4y = -21 becomes 0 - 4(-3/2) = -21, which is true.
Therefore, (x, y) = (0, -3/2) or (0, 21/4) is the correct solution to the system of equations.
User Joel Holmes
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