2(b-5)+7b-4
Solve 2(b-5) to get 2b-10
Combine your like terms 2b-10+7b-4
Solve 2b+7b to get 9b
Solve -10+(-4) to get -14
So your answer is
9b-14
Root 25 is the rational number as it equals 5
X × 75% = £45
x = £45 / 75%
x = £45 / 0,75
x = £60
"that were...."
-For my concern, please give more detail about this question and possibly explain.
Answer:
The volume increases at a rate of 
Step-by-step explanation:
The rate of change of the radius with respect to time is 4 mm / s.
So:

Now we must find a relationship between the volume of a sphere and its radius.
The equation of the volume of a sphere is:

So:

The diameter of the sphere is 100 mm. Therefore its radius is 100/2 = 50 mm.
So:

The volume increases at a rate of :
40000 π mm ^ 3 / s = 125663.71 mm^3/s