18. s = 5r^2 + 7......making r the subject
s - 7 = 5r^2
(s - 7) / 5 = r^2...by taking the sqrt of both sides, it eliminates the ^2
( sqrt (s-7)/5) = r
19. h = ut - 1/2gt^2....u = 100, t = 1 4/5(or 9/5)...g = 6.4
h = (100)(9/5) - 1/2(6.4)(9/5^2)
h = 180 - 1/2(6.4)(3.24)
h = 180 - 3.2(3.24)
h = 180 - 10.368
h = 169.632 or 169 79/125
20. sorry..do not know this one
I can't see what expressions you had posted. Maybe you didn't typed it out, but 649*36=23364
Answer:
No solutions
Step-by-step explanation:
Isolate the absolute value:
|x−1| + 5 = 2
Subtract 5 from both sides:
|x-1| = -3
Since an absolute value can never be equal to a negative number, there are no solutions.
Do what is in the parentheses then add
Answer: The waiting time will be 32 minutes when 240 people in line.
Step-by-step explanation:
Let us assume that the waiting time is directly proportional to the number of people in the queue.
Equation of direct proportion between variables x and y : 
Put
to find
.

Hence, the waiting time will be 32 minutes when 240 people in line.