What is y if x equals 5.

y=-4x^2-3x+4

-4 x 5^2 - 3 x 5+ 4

Thats the same equation, with 5 instead of X.

No parantheses, so we do the exponents first. 

5^2 = 25

so

-4 x 25 - 3 x 5 + 4

Next: Multiplication. 

-4 x 25 = -100
3 x 5 = 15

-100 - 15 + 4

Next: Addition:

-100 - 19

which equals 

-119