How do you solve $7 x - y = 44$ $7x-y=44$ and $x + 4 y = 27$ $x+4y=27$ by elimination?

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How do you solve $7 x - y = 44$ $7x-y=44$ and $x + 4 y = 27$ $x+4y=27$ by elimination?

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Answer 1 · 2017-02-14T13:51:50

Not sure what you mean by "elimination" but I do it this way.....

Explanation:

First, $7 x - y = 44$ $7x - y = 44$ therefore $7 x = 44 + y$ $7x = 44 + y$ and $x = \frac{44 + y}{7}$ $x = (44 + y) / 7$
Also, $x + 4 y = 27$ $x + 4y = 27$ therefore $x = 27 - 4 y$ $x = 27 -4y$

Therefore $44 + y = 7 . (27 - 4 y)$ $44 + y = 7.(27 - 4y)$
And therefore $44 + y = 189 - 28 y$ $44 + y = 189 -28y$ by multiplying out the bracket.
So $y + 28 y = 189 - 44$ $y + 28 y = 189 -44$
And $29 y = 145$ $29 y = 145$
Therefore $y = \frac{145}{29} = 5$ $y =145/29= 5$ .

And we already know that $x = 27 - 4 y$ $x = 27 - 4y$
So substituting in y we get $x = 27 - (4.5) = 27 - 20 = 7$ $x = 27 - (4.5) = 27 -20 = 7$ .

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How do you solve $7 x - y = 44$ $7x-y=44$ and $x + 4 y = 27$ $x+4y=27$ by elimination?

1 Answer

Explanation:

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How do you solve 7x−y=447x-y=44 and x+4y=27x+4y=27 by elimination?

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How do you solve $7 x - y = 44$ $7x-y=44$ and $x + 4 y = 27$ $x+4y=27$ by elimination?