Sarah said when x=3 then the value of 4x squared is 144

holly said when x=3 then the value of 4x squared is 36

who is right and why?

3 answers

Holly if you have 2 expressions like this...4(x+1) Times 4(x+1) where x=3 then by substitution 4(3+1) Times 4(3+1) = 16 x16 or 256
Is it? 4X^2 or (4x)^2.

4X^2 = 4*3^2 = 4*9 = 36.

(4X)^2 = (4*3)^2 = (12)^2 = 144.
Sarah