Question

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

Answer 1

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

Explanation:

First, `7x - y = 44` therefore `7x = 44 + y` and `x = (44 + y) / 7`
Also, `x + 4y = 27` therefore `x = 27 -4y`

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

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