Question

How do you solve the following system: #y=4x+4, 6x + 7y = -9 #?

Answer 1

Well... you already have `y's` value from the first equation but I'm am gonna go ahead and take out `x` value too

`1^(st)" equation"`

`color(blue)(y=4x+4`

`y-4x=4`

`-4x=4+y`

`color(blue)(x=-(4+y)/4`

`2^(nd) " equation"`

`6x+7y=-9`

`6(4x+4)+6x=-9`

Factorize `6` out of them

`6((4x+4)+x)=-9`

Transfer 6 and add

`4x+4+x=-9/6`

`5x+4=-3/2`

Transfer `4`

`5x=-3/2-4`

Make the denominators common

`5x=-3/2-8/2`

`5x=-11/2`

Transfer `5`

`x=-11/10`

`color(Red)(x=-1.1`

`y=4x+4`

`y=4xx-11/10+4`

`y=-44/10+4`

`y=-4.4+4`

`color(red)(y=-0.4`