I believe it is corresponding to the value of x in type of situational problem.
Divide everything by 4 getting:
7y=3x+21
then get all of the variables on one side by subtracting 3x:
7y-3x=21
F = 9/5C + 32
Subtract 32 to both sides:
F - 32 = 9/5C
Divide 9/5 to both sides or multiply by its reciprocal, 5/9:
5/9(F - 32) = C
Simplify:
C = 5/9F - 160/9
Hello!
1 minute 3 seconds = 63 seconds
We must found out 63 is 90% of what number, using the percentage formula:
90 * 100 / 63 = 70
70 seconds = 1 minute 10 seconds
So, Niki's time for one lap is 1 minute 10 seconds (70 seconds).
