Answer:
x= 7
y=9
z=90
Step-by-step explanation:
8x = (9x-7)
8x = 9x-7
8x - 9x= -7
-x= -7
(multiply -1 to each side to make it positive)
x= 7
(5y-11)+(9x-7)=90
5y-11+9(7)-7=90
5y-11+63-7=90
5y+63-18=90
5y+45=90
5y=90-45
5y=45
y=45÷5
y=9
(5y-11)+8x+z=180
5y-11+8x+z=180
5(9)-11+8(7)+z=180
45-11+56+z=180
34+56+z=180
90+z=180
z=180-90
z=90
