Answer:
b. 4x^2 -7x +5
Step-by-step explanation:
When you know a sum and one of its contributors, you can find the other by subtraction. The other trinomial is ...
(7x^2 -5x +4) - (3x^2 +2x -1)
= (7 -3)x^2 +(-5 -2)x +(4 -(-1))
= 4x^2 -7x +5 . . . . . matches B
Answer:
12.75
Step-by-step explanation:
12.75 rounded to the nearest tenth is 12.8, and 12.74 won't work because it will round to 12.7.
Therefore, 12.75 is the smallest possible number.
You already know what it is cuh
Set up a proportion. 2/5 = x/40
to solve the equation first cross multiply.
x*5=40*2
x*5=80
now divide both sides by 5, 80 divided by 5 is equal to 16.
so the number of girls in the computer lab is 16.
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.