Solve for each of the systems 3z+8x=135 and 7z + 8x = 155

Asked by AnneS2 on 20 Jul 05:39

Last updated by anonymous on 22 Jul 11:31

Answered by CherieS on 22 Jul 11:31

3z+8x=135

3z+8x-8x=135 -8x

3z=135 -8x

3z/3=135 -8x/3

z=45-2.67x

7z + 8x = 155

7(45-2.67x) + 8x = 155

7(45) (7)(-2.67x) + 8x = 155

315-18.69x+8x=155

315-10.69x=155

315-10.69x-315=155-315

-10.69x=-160

-10.69x/-10.69=-160/-10.69

x=14.97

z=45-2.67x

z=45-2.67(14.97)

z=45-39.97=5.0