Answer:
81
Step-by-step explanation:
9^2 = 81 bc 9x9=81
I’m not exactly sure what you mean by “write it in math,” however I can tell you what I think.
4y=x
(It says that x is 4 times the value of y which means that y times 4 is x.)
Y = -5x +18
x can be any number, y can be change due to x value
