Question

Given 4x = 7 y - z, solve for y if x = 8 and 7z = -4.

Answer 1

We have the following equation given:

`4x=7y-z`

We need to solve for y when x=8 and 7z=-4. If we solve for y we got:

`7y=4x+z`

And dividing both sides by 7 we got:

`y=(4x+z)/(7)`

We can use the condition 7z=-4 in order to solve for z and we got:

`z=-(4)/(7)`

Now we can replace x and z in order to solve for y and we got:

`y=(4(8)+(-(4)/(7)))/(7)=(32-((4)/(7)))/(7)=(220)/(49)`