9f+3.6=10.8

what is the answer
what does f stand for
plz help asap

f=0.8

9f+3.6=10.8

Subtract 3.6 from both sides

9f=7.2

Divide both sides by 9

f = 0.8

Area of a square is length by width

So area = (4+x) (4 + x)

Apply FOIL (first, outer, inner, last) to solve this:

(4 ⋅ 4) = 16

(4 ⋅ x) = 4x

( x ⋅ 4) = 4x

(x ⋅ x) =

16 + 4x + 4x +

              =   + 8x + 16 (this is the area of the square)

Happy to help!