Question

help, please
4x + 5y + z = $23

6x + 6y = $30

3x + 7y + 5z = $28

Answer 1

you looking for x & y on all of these ?

Answer 2

and z

Answer 3

from the second :
(let me ignore the $ sign)
x + y = 5
so
x = 5-y

plug it into the first:
4(5-y) +5y + z =23
20 - 4y + 5y +z = 23
y + z = 3
y = 3-z

so we have
y= 3-z
so we can write x = 5-y in terms of z :
x = 5-(3-z) = 2 + z

plug it into the last equation:

3(2+z) +7(3-z) + 5z = 28
27 +z = 28
z = 1$

so
x= 3$
and
y= 2$