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3 years ago

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5x + 4y = 17 Y - x = 2 x = y = please help

1 answer:

Tasya [4]3 years ago

5 0

I will solve this equation simultaneously by Substitution.

- x + y = 2
5x + 4y = 17

Solve - x + y = 2 for y:
- x + y + x = 2 + x (here we add x to both sides)
y = x + 2

Substitute x + 2 for y in 5x + 4y = 17
5x + 4y = 17
5x + 4(x + 2) = 17
5x + 4x + 8 = 17
9x + 8 = 17 (simplify both sides of the equation)
9x + 8 + (-8) = 17 + (-8) (add -8 to both sides)
9x = 9
9x/9 = 9/9 (divide both sides by 9)

x = 1

Substitute 1 for x in y = x + 2
y = x + 2
y = 1 + 2
y = 3 ( simplify both sides of the equation)

Therefore x = 1 and y = 3

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