Answer: 81
Step-by-step explanation: Because, (-3)^4=-3*-3*-3*-3=-(-81)=81
7•x=x-15
I think this would work, if I understood what you were saying correctly.
Answer: 27 and 18
Step-by-step explanation:
x - y = 9 → x = 9 + y
3y = 2x
3y = 2(9 + y)
3y = 18 + 2y
3y - 2y = 18
y = 18
2x = 3(18)
2x = 54
x = 27
x - y = 9
27 - 18 = 9
9 = 9
