step-by-step explanation:
given perimeter: 28cm
length: 9cm
atp,
2(l+w)=p of the reactangle
2(9+x)=28
18+2x=28
2x=28-18
x=10/2
x=5
therefore width is 5 cm
you can first factor out the n to get n(1+5). we know that 1+5 is 6, so we just have 6n.
the 3rd on is correct
answer: b.36 feet