Question

Someone who solves it by reduction method ?:(

`3x - 7y = 38`
`7x + 4y = 48`

Answer 1

`x=8" "` and `" "y=-2`

Explanation:

Given:

`{ (3x - 7y = 38), (7x + 4y = 48) :}`

Multiply the first equation by `4` and the second by `7` so that the coefficients of `y` will cancel:

`{ (12x - 28y = 152), (49x + 28y = 336) :}`

Then adding the two equations, we find:

`61x = 488`

Dividing both sides by `61`, we find;

`x = 8`

Going back to the original equations, we could substitute this value for `x` into one of them and hence find `y`, but instead let us multiply the first equation by `7` and the second by `3`, to make the coefficients of `x` cancellable:

`{ (21x - 49y = 266), (21x + 12y = 144) :}`

Subtracting the first of these equations from the second, we find:

`61y = -122`

Then dividing both sides by `61`, we find:

`y = -2`