Answer:
Answer 4. (5 1/3 hours)
Step-by-step explanation:
240/45=5.333333333
Answer:

Step-by-step explanation:
I supposed that is a "n".
Steps as below:

Answer:
One number is 17 and the other is 85.
Step-by-step explanation:
Let the numbers be m and n. Let m = (1/5)n. Note that m+n = 18.
Substituting (1/5)n for m in the 2nd equation, we get (1/5)n + (5/5)n = 18. Multiplying all three terms by 5 to remove fractions, we get n + 5 = 90, so that n = 85. m is (1/5) of 85, or m = 17.
7.5 xxx. 8.0 xxx 8.5 xxx 9.0 xxxxx 9.5 xxxx
-2(-5x+9)-9x
-2(-5x)+-2(9)-9x
10x-18-9x
+9 +9
19x=-18
---- ----
19 19
x=-1.05