Area of deck= 2(20w)+4(w^2)+2(50w)d
456=2(20w)+4(w^2)+2(50w)
456=40w+4w^2+100w
456=4w^2+140w
114=w^2+35w
0=w^2+35w-114
find what 2 numbers multiply to get 114 and add to get 35 and factor
-3 and 38
0=(w-3)(w+38)
set each to zero
w-3=0
w=3
12 sqrt3 * 2 sqrt2 * 3
= 24 sqrt6 * 3
= 72 sqrt6 answer
No because if it is a square all the sides are 7m long so a 9m plank will not fit. Hope this helps.
Part A:5=2x^2-x^2+13
5=x^2+13
0=x^2+13-5
0=x^2+8
Part B:5=2x^3-x^3+13
5=x^3+13
0=x^3+13-5
0=x^3+8
