c.
The number of students is represented with S, to show 2 times that number it is shown as 2S, a less than is word problem jargon for minus. So it is 2S-21.
2.507
......................................
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
Explanation
We are asked to give a counter-example for the given statement
A counter-example is an example that opposes or contradicts an idea or statement.
Therefore, for the statement
we have that
Statement: If an appliance is used for cooling
Conclusion: then it is a refrigerator
Then, the option that contradicts this, will be a clothes dryer
Because a dryer doesn't cool
Hence, the answer is a cloth dryer
option D
Answer:
125
Step-by-step explanation:
All the work is in picture attat