Answer:
1. y = 7x. This is an example of direct variation as the value of y also increases if the value of x is increased.
2. xy = 24. This is an example of inverse because the value of y is decreased when x is increased.
3. F = 4/R. This is inverse variation for the same reason as number 2.
4. m/n = 4. Direct variation. For the same reason as number 1.
5. i = 2pr. Joint variation. The value of i is dependent on the values of two other variables.
6. R = cl/r². Joint variation.
7. A = pir². Direct variation. I believe pi here is for π, leaving only A being dependent only to value of r.
8. V= pir²h. Joint variation.
Step-by-step explanation:
If you multiple 128 by 6 you will get your answer of 768.
36 divided by 90 gives the percent so its 0.4 which is 40%
7. X2=25
X=5, x=—5
8. (X—3)2=49
X=10, x=—4
9. X2+3x—28.
X=4, x=—7.
10. 5x2–8=3x.
X=8/5, x=—1