Answer:
or 
Step-by-step explanation:
We use casework on when
and when
.
For the first case,
, we add 9 to both sides to get
.
Dividing both sides by 3 gives

For the second case,
, we add 9 to both sides to get
.
Dividing both sides by 3 gives
.
Checking both cases, we plug in
and
.
For the first case, we have
, which satisfies the equation.
For the second case, we have
, which also satisfies the equation.
This gives us two solutions to the equation;
and
.
Answer:
Your answer should be $29.40
Step-by-step explanation:
If you divide 21 by 5 you get 4.2, so each book costs $4.20.
4.2 x 7 = 29.4
Therefore, your total cost for 7 books will be $29.40
I hope this helps!
All estimating problems make the assumption you are familar with your math facts, addition and multiplication. Since students normally memorize multiplication facts for single-digit numbers, any problem that can be simplified to single-digit numbers is easily worked.
2. You are asked to estimate 47.99 times 0.6. The problem statement suggests you do this by multiplying 50 times 0.6. That product is the same as 5 × 6, which is a math fact you have memorized. You know this because
.. 50 × 0.6 = (5 × 10) × (6 × 1/10)
.. = (5 × 6) × (10 ×1/10) . . . . . . . . . . . by the associative property of multiplication
.. = 30 × 1
.. = 30
3. You have not provided any clue as to the procedure reviewed in the lesson. Using a calculator,
.. 47.99 × 0.6 = 28.79 . . . . . . rounded to cents
4. You have to decide if knowing the price is near $30 is sufficient information, or whether you need to know it is precisely $28.79. In my opinion, knowing it is near $30 is good enough, unless I'm having to count pennies for any of several possible reasons.
Answer:
approximately 56.51 cubic inches
Step-by-step explanation:
volume of a cone = 1 / 3 × pi × radius^2 × height
= 1/3 × 22/7 × 7.29 × 7.4
= 56.5148 cubic inches
Answer:
It will take him 1 hour and 30 minutes. (90 minutes)
Step-by-step explanation:
If he is running 1 mile in 10 minutes and he needs to run 9 miles the just multiply 9 by 10 to get 90 then simplify if you need to to get 1 hour and 30 minutes.
Hope this helped and have a great rest of your day.