# algebra

posted by .

A heating duct has a rectangular cross section whose area is 40(inches squared).
If it is 3in longer than it is wide then what is its length and width. i need both equation and answer

• algebra -

Area = Length * Width

If W = x, then L = x+3

40 = x^2 + 3x

x^2 + 3x - 40 = 0

(x+8)(x-5) = 0

For each possible value of x, find x+3.

• algebra -

x cannot be negative, so only one of the two possible number for x is correct.

## Similar Questions

1. ### basic geometric

10. a rectangle has width the same as a side of a square whose perimeter is 20m. the length of the rectangle is 9m. find the perimeter of this rectangle. 34. The width of a rectangular picture is one-half the length. The perimeter …
2. ### Algebra 2( it's a tough one!)

Jose needs to enclose a rectangular section of his yard. The area is 35 sq. ft. and the perimeter is 27 sq. ft. Find the length and width of the section. let l be the length, and w be the width in feet. so 2l+2w=27 --->l+w=13.5 …
3. ### math

I need help with this question... Find the area of a rectangular garden whose length is 8 feet and whose width is 72 inches.
4. ### algebra

I need help with this question... Find the area of a rectangular garden whose length is 8 feet and whose width is is 72 inches.
5. ### Algebra

A rectangular counter top is 16 inches longer than it is wide. If the area of the counter top is 420 square inches, find the length and the width.
6. ### Algebra

Find the area of a rectangle heating-duct grill having a length of 2yd and a width of 17/4yd
7. ### pre-calc

construction of a rain gutter: a piece of rectangular sheet metal is 20 inches wide. it is to be made into a rain gutter by turning the edges to form parallel sides. let x represent the length of each of the parallel. a) give the restrictions …
8. ### algebra

The rectangular floor of a shed has a length 4 feet longer than its width, and its area is 140 square feet. Let x be the width of the floor. (a) Write a quadratic equation whose solution gives the width of the floor. (b) Solve this …
9. ### spc

a long strip of sheet metal 12 inches wide is to be formed into an open gutter with a rectangular cross-section as shown. what is the maximum possible area of the cross-section?
10. ### Algebra Homework, HELP!

1) A rectangle has an area of 297 square inches and a width which is three inches less than four times the length. Find the length and the width of the rectangle. 2) Let x represent the length of the shorter leg in a right triangle. …

More Similar Questions