Pencils cost 9p each. How much would 28 pencils cost?
1 answer:
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Answer:
(1) P=4a+4
(2) P=2a+4a
Step-by-step explanation:
Well, let us call longer side b, shorter side a and diagonal d. The perimeter of a rectangle is 2*(a+b). Let us write this formula as P=2*(a+b)
In (1) it is stated that b=a+2. Hence, the perimeter of the rectangle is P=2*(a+b). In terms of b, let us write (a+2). So P=2*(a+a+2)=4a+4.
In (2) it is stated that d/a=13 or d=13a. From Pythagorean theorem d^2=a^2+b^2. Hence, b^2=168a^2 or b=2a. Finally, P=2*(a+b)=2*(a+2
a)=2a+4
a