Which is the value of 3b2-b when b=5?
a.20
b.25
c.70
d.75

3b2-b, we can re-write it as 6b-b

Now, substitute for b=5,

6(5)-5 = 30-5 =25

SO, OPTION B WOULD BE THE ANSWER.

 The correct option is (c) 70.

Step-by-step explanation:  We are given to find the value of the following expression for b = 5 :

To find the value of the expression (i) at b = 5, we need to substitute b = 5 in (i).

Substituting b = 5 in (i), we get

Thus, the required value of the the given expression is 70.

Option (c) is CORRECT.

answer: it's a

step-by-step explanation:

step-by-step explanation:

12: 00 p.m. to 7: 00 p.m. is a total of 7 hours.

4: 00 p.m. to 7: 00 p.m. is a total of 3 hours.

this means that from 4: 00 p.m to 7: 00 p.m. this represents 3/7 of what was lost from 12: 00 p.m. to 7: 00 p.m.

after knowing this, after doing 11,600 - 6,800 = 4,800

4,800 represents 3/7 of what was lost for 7 hours.

we then divide 4,800 by 3 which gets 1,600.

because we know that 1,600 represents 1/7 of how much water was lost, we just have to multiply by 7, which gets 11,200.   after adding 11,200 to how much water was left at 7: 00 p.m. which was 6,800. 11,200 + 6,800 = 18,000

this means that the pool originally had 18,000 gallons in the pool.

you can also check your work by doing 18,000 - 4(1600), which becomes           1800 - 6400 which gets you 11,600.