£480
2:3:7 = 2+3+7 = 12
2
--- 0f £480 = £80
12
3
--- of £480 = £120
12
7
--- of £480 = £280
12
answer = £80 : £120 : £280
Ahhh bet your a female right?
The missing number is the square-root of the constant term on the left-hand-side, which equals sqrt(1/16)=1/sqrt(16)=1/4.
Check:
(x+1/4)^2=x^2+2*(1/4)x+(1/4)^2=x^2+x/2+1/16. ok
Answer: x= 1/4
18.75÷5=3.75
12.75÷3=4.2
The pack of 5 books has the lower cost per book
