Homework Help: Math

Posted by Michelle on Wednesday, April 29, 2009 at 8:14pm.

I'm doing some word problems on finding the areas of rectangles, its just like all complicated. I don't understand how to do them. For example:

A square field had 3 m added to its length and 2m added to its width. The area is 90 m2(squared). Find the length of a side of the original field.

So first you get (x+3)(x+2)=90, right?
then you get x2+5x+6=90
then x2+5x=84

How do you go on? How do you figure out x? I don't get it! I have other problems like those, could you tell me how to figure out a problem with x2 and something x = a number in general? Please help!

Math - Quidditch, Wednesday, April 29, 2009 at 8:23pm
Take your step:
x^2 + 5x + 6 = 90
Now:
x^2 + 5x - 84 = 0

Factor by inspection or use the quadratic formula to solve for x.
A hint is what two factors of 84 differ by 5?

Answer this Question

Related Questions

Math - Estimate the are under the curve f(x)=x^2-4x+5 on [1,3]. Darw the graph ...
Math: Need Answer to study for a quizz. Help ASAP - Estimate the area under the...
want to know-math - Substitution can also involve more complicated problems, ...
5th grade math (word problems) - I didn't see an answer from yesterday, so ...
math - On a centimeter dot array, draw all possible rectangles with a perimeter ...
question - Why are finding solutions to environmental problems so complicated?
Math - I need help on problems like -8*29 i dont understand what to do. i also ...
Geometry - the ration if the side lengths of two similar rectangles is 4:3. ...
sentence patterns - we need some help.We write tomorrow an exam-sentence ...
Math - Can somebody help me out here. I want to know why I am good with math ...

For Further Reading

First Name:
School Subject:
Answer: