4.167 I think but I'm not completely sure
Answer:

Step-by-step explanation:
The scientific notation:

We have:

21.8 >10
21.8 = 2.18 × 10
Thereofre:

Use


Answer: 5c+3
Step-by-step explanation: divide regularly. Just keep the C after the 10. I'm not good at explain math sorry.
X+40=4x+10
4x-x=40-10
3x=30
x=10 miles
<em><u>Answer: 10 miles</u></em>
5. 14 squared centimeters
6. 31 7/8 squared inches
7. 936 squared inches
8. 125 squared centimeters
9. 72 squared meters
10. 336 squared meters
11. 8.25 squared feet
12. 187.5 squared inches
13. 1,620 squared inches
14. 300 squared feet; trapezoid's equation was (10+18)6/2. For the rectangle, equation was 18x12. Add the answers together to get 300.
I hope this helped! :)