When you are multiplying exponents with the same base, you can add the exponents. This is represented as:
In our case we are multiplying exponents with the same base 8 and exponents -7 and 5. The sum of -7 and 5 is -2, so our answer is 
.
9n + 15 < = 10n + 24
9n - 10n < = 24 - 15
-n < = 9
n > = -9
Step-by-step explanation:
The easiest approach is to realise that one hour is 3 times longer than
20
minutes. The longer the time, the more they will pave.
2
15
of a mile, in 20 minutes, how much in 60 minutes?#
They will pave 3 times more.
2
15
×
3
1
=
6
15
of a mile
6
15
=
2
5
of a mile
You could also use the 'unitary method' where you find out how much they pave in ONE minute (divide by
20
) and them multiply by
60
to find how much in one hour.
Look at what happens:
2
15
÷
20
×
60
=
2
15
×
1
20
×
60
3
=
2
15
×
3
←
exactly the same maths.
=
2
5
Answer: $180
4ft + 5ft + 4ft + 5ft = 18ft
18 x 10 = 180
