hey everybody(Speechless)

i couldnt figure out this question from a past paper about quadratic formula

it was pretty straight foward-

the total area of rectangle R and Q is 64cm^2

calculate the value of x correct to one decimal place

5x^2+30x+24

i got 0.95 (for subtraction) and 5.05

i am jus confused on what i am suppose to choose so that the answer is 64

plus forgot what it meant by correct to one decimal place...was it rounding up? (Worried) ...n also 3 significant figures....actually i m mixed up in both of them -.-

thanks