Answer:
7. 3/9
Simplify.
= 1/3
≈ 0.6666666667
8. 13.2(0.4)
Multiply.
= 5.28
9. 5/7(7/12)
Reduce the numbers with the GCF 7.
= 5/12
≈ 0.416
10. ⅔ / ⅕
Multiply by the reciprocal of ⅕.
⅔(5)
Multiply.
= 10/3
≈ 3.3333333333
11. 80(0.4)
Multiply.
= 32
12. n - 10 = 8
Move -10 to the right hand side and change it's sign.
n = 8 + 10
Add.
n = 18
13. 180 + 20 / 2 x 3 - (13 - 3)
Using GEMDAS, subtract the terms in the group.
180 + 20 / 2 x 3 - 10
Multiply.
180 + 20 / 6 - 10
Divide.
180 + 3.3333333333 - 10
Add.
183.3333333333 - 10
Subtract.
= 173.3333333333
≈ 173 ⅓
≈ 520 / 3
14. 75 - 39 = x + 4
Subtract.
36 = x + 4
Move the variable into the left hand side and change it's sign then move the constant into the right hand side and change it's sign.
-x + 36 = 4
-x = 4 - 36
Subtract.
-x = -32
Simplify.
x = 32
15. In a day, there is 24 hours, so subtract 8, 5 and 6 by 24.
24 - (8 + 5 + 6)
Add.
24 - 19
Subtract.
= 5 hours
16. P = a + b + c, a = 10, b = 8, c = 6
P = 10 + 8 + 6
P = 24cm
17. 40(¼)
= 10 marbles
18. 100 - 23
= 77th block
19. 30(5)
= 150 words
20. (78 + 82 + 80 + 84) / 4
324 / 4
= 81
Hope this helps. ^^
