Step-by-step explanation:

I think X is 2. But I am not sure, cuz I don’t know what you teacher is really asking you to do.
Answer:
27.8
Step-by-step explanation:
You need to do brackets first
3.6-1.8 = 1.8
Then substitute
4.5 x 8- (0.4 + 9.6- 1.8)
0.4+9.6-1.8=8.2
4.5 x 8 - 8.2 =27.8
Y= f(x) = a+bx
example: f(x) = 3x+2