23,039.
y=13,000(1.045)^t
t=13
You get 1.045 because you add 1+ the percentage in decimal form.
The property used is the Associative property
3 × 70 = 3(70) = 3 (7×10) = (3×7) ×10
The formula is
a × bc = a (bc) = a (b×c) = (a×b) ×c
Answer:
increase = 37.38 cm²
You'd like the first way because it took less effort and less chance of a miscalculation.
Step-by-step explanation:
first way:
(just work with the difference in height)
(0.7 x 8.7 x 2) + (0.7 x 18 x 2) = 37.38 cm²
second way:
old total lateral surface area = (31 x 8.7 x 2) + (31 x 18 x 2) = 1655.4
new total lateral surface area = (31.7 x 8.7 x 2) + (31.7 x 18 x 2) = 1692.78
increase = 1692.78 - 1655.4 = 37.38 cm²
Divide 31 by 50 and that will give you .62 move the decimal point two places to the right and that gives you 62%. :)