A = L * W
A = 70
70 = L * W
P = 2(L + W)
P = 34
34 = 2(L + W)
34/2 = L + W
17 = L + W
17 - W = L
70 = L * W
L = 17 - W
70 = W(17 - W)
70 = -W^2 + 17W
W^2 - 17W + 70 = 0
(W - 10)(W - 7) = 0
W - 10 = 0 L = 17 - 10
W = 10 L = 7
W - 7 = 0 L = 17 - 7
W = 7 L = 10
so either the width is 10 meters and the length is 7 meters OR the width is 7 meters and the length is 10 meters
I did my best to explain it on graph paper. I hope this helps! Look at the attached picture.
(n+12)(n-7) = n^2 + 5n - 84
Answer:
3 letters can be arranged in 26*25*24 = 15600 ways
3 digits can be arranged in 10 * 9 * 8 = 720 ways
So the total number is 15600 * 720 = 11,232,000
So I agree with the number that you obtained
3.691 rounded by the nearest tenth is 3.7