Answer:

Step-by-step explanation:
Isolate the variable by dividing each side by factors that don't contain the variable.
Answer:
7 hours
Step-by-step explanation:
9 : 30 to 17:00 = 7 hours 30 minutes
Minus 30 minutes = 7 hours
Both of them together have 690 because you subtract 152 from 421 so...
421-152=269
Then add 269 to 421
421+269=690
I FOUND YOUR COMPLETE QUESTION IN OTHER SOURCES.
PLEASE SEE ATTACHED IMAGE.
First, we define the variables:
x: number of years after 1950
f (x): amount of vinyl sold.
Then, with the variables defined, we have:
68594 vinyl records were sold in 1958 ---------> f (8) = 68594
91299 vinyl records were sold in 1961 ---------> f (11) = 91299
38720 vinyl records were sold in 1952 ---------> f (2) = 38720
161743 vinyl records were sold in 1967 ---------> f (17) = 161743