The length of a rectangle is 4 more than the width. The area is 5 square inches. Find the dimensions.

Please walk me through it, I want to find the answer, I just need help getting there. :)

Question

The length of a rectangle is 4 more than the width. The area is 5 square inches. Find the dimensions.

Please walk me through it, I want to find the answer, I just need help getting there. :)

anonymous · Answer

If the width is x, then the length is x+4. You have to multiply both of them together to get the area, 5.
Can you write the equation for this?

anonymous · Answer

5=x(x+4)?

anonymous · Answer

Exactly! Can you expand that now?

anonymous · Answer

$$5=x^2+4x?$$

anonymous · Answer

Good, now you need to move the 5 onto the other side so you can factor and solve for x.

anonymous · Answer

$$x^2+4x-5=0$$

anonymous · Answer

Can you factor that?

anonymous · Answer

What are the factors of -5 that add up to 4?

anonymous · Answer

5,-1

anonymous · Answer

x+5=0       x-1=0
   -5-5         +1 +1

x=-5             x=1

anonymous · Answer

Right, so it is't possible for lengths to be negative so the answer is x=1. If the width is 1, then the length would be?

anonymous · Answer

uhh, 5?