SOLUTION: The width of a rectangle is (3x − 1) in. The length of the rectangle is twice the width. Find the area of the rectangle in terms of the variable x.

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: The width of a rectangle is (3x − 1) in. The length of the rectangle is twice the width. Find the area of the rectangle in terms of the variable x.      Log On


   



Question 615833: The width of a rectangle is
(3x − 1)
in. The length of the rectangle is twice the width. Find the area of the rectangle in terms of the variable x.

Answer by dragonwalker(73) About Me  (Show Source):
You can put this solution on YOUR website!

Please note that I have used * to represent a multiply sign.
As the length of the rectangle is twice the width then you need to multiply the width of the rectangle by 2.
As follows:
2 * (3x - 1) = 2(3x - 1)
you multiply each part of the formula by two as follows:
(2*3x - 2*1) = (6x - 2)
So the length is (6x - 2)
To find an area of a rectangle you then need to multiply the width by the length:
Area = (3x - 1)*(6x - 2) or more correctly written:
(3x - 1)(6x - 2)
To solve this you have to multiply each number in the first bracket by each number in the second unit so:
i.e. let us say we have (a + b)(c + d):
we have to do the following:
a*c a*d then b*c and b*d
So for our formula:
(3x - 1)(6x - 2) = 3x*6x + 3x*-2 + -1*6x + -1*-2
= 18x%5E2+%2B+-6x+%2B+-6x+%2B+2
as + - together makes a - :
= 18x%5E2+-+6x+-+6x+%2B+2
= 18x%5E2+-+12x+%2B+2