Algebra 1

[lissy_roxs]

I have a question i just dont really understand...
Assume that the perimeter of a pentagon whose perimeter is 4a+4 is three times the perimeter of a triangle whose perimeter is a+3. A. Find a. B.calulate the perimeters of both the triangle and the pentagon.

 

[daon]

Let us decode this problem.

Perimeter of the rectangle = 4a+4, for some unknown value a.
Perimeter of the triangle = a+3, for the same unknown value a.

(The perimeter of a pentagon) is [three times] (the perimeter of the triangle)

"is" means equals, so:

(4a+4) = [three times] (a+3)

So you need to solve: \(\displaystyle 4a+4 = 3(a+3)\)

 

[mmm4444bot]

The expression 4a + 4 represents some number.

The expression a + 3 represents some other number.

We're told that the first number is three times larger than the second number.

In other words, if we multiply the second number by 3, the product will equal the first number.

3(a + 3) = 4a + 4

Solve for a.

Once you know the value of a, you can easily calculate both numbers to answer part (B).