Yup! We're all pretty good here. :)
You can use factors to solve. Determine all the factor pairs of 24, find the two that are two numbers apart.
1, 24 X
2, 12 X
3, 8 X
4, 6 YES!
Algebraic way to solve using Quadratics:
l = 2 + w
A = lw
A = (2 + w)w Substitute (2 + w) for l
24 = (2 + w)w Substitute 24 in for the area
24 = 2w + w^2 Distribute
w^2 + 2w - 24 = 0 Set equal to 0 (put in standard form)
(w + 6) (w - 4) = 0 Factor
w + 6 = 0 and w - 4 = 0 Set each factor equal to 0.
So w= -6 or w = 4 ... -6 makes no sense for a length! So the width must be 4 and the length will be 4 + 2, which is 6.
Answer:
7 cm
Step-by-step explanation:
SA = 208 cm^2
SA= 2*a*b + 2*a*c + 2*b*c
where:
a= first dimension = 2 cm
b= second dimension = 10 cm
c= third dimension
so we have:
208= 2*2*10 + 2*2*c + 2*10*c
208= 40 + 4c + 20c
208-40= 24c
168=24c
c =168/24
c = 7cm = third dimension
The answer is the first option, 3/1
