4 more than a number = x + 4
is more than = >
thirteen = 13
x + 4 > 13
8x+15=7
In the statement the phrase the sum of can tell you that it is going to be an addition problem. So 8x ( eight times a number) would be added to the 15, 8x+15. Since its an addition problem the part where it says ' ... is seven', you know that it will all equal 7. So the answer would be 8x+15=7.
Mark and Don have to sell 11 and 59 marbles respectively.
<em><u>Explanation</u></em>
Lets assume, the number of marbles Mark has is 
As, Don has 4 more than 5 times the number of marbles mark has, so the number of marbles Don has 
Question says that the total number of marbles is 70. So, the equation will be...

<em>So, the number of marbles Mark has = 11 </em>
<em>and the number of marbles Don has =
</em>
Answer: 3 ft. and 2 inches
38÷12=3.2
12×3=36
38-36
The volume of a box like this is found by multiplying the length times the width times the height. We are told that the length is 8 more inches than the width, so the width is w and the length is w + 8. If we cut away 3 square inches from each corner, the height when we fold up those corners is going to be 3. The volume is given as 27, so our formula looks like this:

. When we do that multiplication, we have

. We need to solve for w so we can then solve for h. Move the 27 over and set the quadratic equal to 0.

. We can then factor out a 3 to make the job easier:

. Now we can factor to solve for w. The 2 numbers that add up to 8 and multiply to -9 are 9 and -1. So (w+9) = 0, (w-1) = 0, or 3 = 0. Of course 3 doesn't equal 0, so that's out. w + 9 = 0 so w = -9. w - 1 = 0 so w = 1. There are 2 things in math that can never EVER be negative and those are time and distance/length. So -9 is out. That means that w = 1. But don't forget that there was 6 inches cut off each side, so the width is 1 + 3 + 3 which is 7. The length is w + 8 which means that the length is 7 + 8 or 15. Those are the dimensions of the rectangle before it was cut.