Looking at number 6, you can guess (the guessing takes a bit of practice so don’t feel bad if you don’t pick up on it right away). Again, looking at number 6, you can see that 3 times 2 give you 6. The next step will be to factor out and make sure your signs are done correctly. The plus and minus signs do get tricky.

Ok, the factored eqution:

(3x-1)(2x+1)

so you have a (3x-1) and a (2x+1) You then substitute 30 for x.

By doing that you will get (90-1) and (60+1) or 89 for length and 61 for width.

89 x 61 =5429 is the area in square units.

You can test your answer by substituting 30 for x in the orginal area formula. If the answer is 5429, then we’re all peachy… [6(30)²+30-1]

so the brief version:

LENGTH = 89

WIDTH= 61

AREA= 5429

A=LW

so factor 6x^2 + x – 1=(3x-1)(2x+1)

now substitute,

so (3x-1)=3(30)-1=89, and (2x+1)=2(30)+1=61

so L=89, W=61,

you can test it if this is right by substitute,

6(30)^2 + 30 – 1

6(900)+30-1

5400+30-1

5430-1

=5429, same as 89 x 61 =5429, so the answer is right.