177k views
1 vote
Josephine has a rectangular garden with an area of 2x2 + x – 6 square feet

Which expressions can represent the length and width of the garden?

length = x2 – 3 feet; width = 2 feet

length = 2x + 3 feet; width = x – 2 feet

length = 2x + 2 feet; width = x – 3 feet

length = 2x – 3 feet; width = x + 2 feet

User Xiaoyi
by
6.1k points

2 Answers

6 votes
factor
2x^2+x-6
trial and error, the factors are the legnth and width
or, we could try multiplying the given options
if we do we find the factored form is
(x+2)(2x-3)
answer is last one
3 votes

we have


2x^(2) +x-6

we know that

The area of a rectangle is equal to


A=L*W

where

L is the length side of the rectangle

W is the width side of the rectangle

In this problem

Equate the area to zero and Find the roots of the quadratic equation


2x^(2) +x-6=0

Group terms that contain the same variable, and move the constant to the opposite side of the equation


2x^(2) +x=6

Factor the leading coefficient


2(x^(2) +0.5x)=6

Complete the square. Remember to balance the equation by adding the same constants to each side


2(x^(2) +0.5x+0.25^(2))=6+0.125


2(x^(2) +0.5x+0.0625=6.125

Rewrite as perfect squares


2(x+0.25)^(2)=6.125


(x+0.25)^(2)=3.0625

Square root both sides


(x+0.25)=(+/-)√(3.0625)


(x+0.25)=(+/-)1.75


x1=-0.25+1.75=1.50


x2=-0.25-1.75=-2

so


2x^(2) +x-6=2(x+2)(x-1.50)


2(x+2)(x-1.50)=(x+2)(2x-3)


length=(2x-3)\ feet


width=(x+2)\ feet

therefore

the answer is the option


length=(2x-3)\ feet ;
width=(x+2)\ feet

User Samuel GIFFARD
by
5.6k points