Could some explain if this = 0 or 45?

I believe the answer is 45

2.5(9)-8(-3)-1.5

22.5--(+)24 -1.5

46.5-1.5=45

I thought so too, but every calculator I used says it's 0 including the one on this site

2.5(-3^2)-8(-3)-1.5 = 0

@rainstraw why? (-3^2) = 9?

Hmm, I can work this out

2.5(-3^2)-8(-3)-1.5=

Parentheses always first

-3^2=-3*-3=9

2.5 * 9 - 8 * -3 -1.5

2.5*9=22.5

-8*-3=24

22.5+24=46.5

46.5-1.5=45 

the true answer is 45, guest is correct

Using PEMDAS, exponentiation takes priority over negation, so most technical calculators will treat -3^2 as -(3^2) = -9 not +9.  This explains why most calculators produce a result of 0 for the given expression.

.

2.5(-3^2)-8(-3)-1.5     first, work inside the parentheses and realize that -3^2  = -9

2.5(-9)  -8(-3) - 1.5   next .... we perform any multiplications/divisions

-22.5 + 24 - 1.5  =

1.5   - 1.5  =

0