This is 4x=2x-2 as a graph
To find the area of a rectangle, multiply its length by its width. I suggest you use a calculator for accuracy in multiplication. Hope this helped!
Paul needs to invest $10000 at 6% interest and $30000 at 10% interest to make a total of 9% return on his $40000.
<em><u>Explanation</u></em>
Suppose, the amount of money at 6% interest is
As Paul has total $40000 to invest, so the amount of money at 10% interest will be: 
His intent is to earn 9% interest on his $40000 investment. So, the equation will be......

So, Paul needs to invest <u>$10000 at 6% interest</u> and ($40000- $10000) or <u>$30000 at 10% interest </u>to make a total of 9% return on his $40000.
Hey there!
This can be written as

This is in form of

, it can be expanded as
=> (n-7)(n+7)=0
=> n -7 = 0 or n + 7 = 0
=> n = 7 or n = -7
So option 7 , -7 are correct.
Hope this is clear :)
Have a good day:)