In order to understand if the inequalities are always, never or sometimes true, you need to perform the calculations:
A) <span>9(x+2) > 9(x-3)
9x + 18 > 9x - 27
the two 9x cancel out and you get:
+18 > -27
which is always true.
B) <span>6x-13 < 6(x-2)
6x - 13 < 6x - 12</span>
</span><span>the two 6x cancel out and you get:
- 13 < -12
which is always true
C) </span><span>-6(2x-10) + 12x ≤ 180
-12x +60 +12x </span>≤ 180
-12x and +<span>12x cancel out and you get:
60 </span><span>≤ 180
which is always true.
All three cases are always true.</span>
Answer: Eleventh Grade
Step-by-step
The ratio of tenth graders to the school's total population is 86:255 = 33.7%.
The ratio of eleventh graders to the school's total population is 18:51 = 35.3%.
Since the probability of a student being in either tenth, eleventh, or twelfth grade = 1 = 100% (that is, certainty), then the probability of a randomly drawn student being in twelfth grade is (100-33.7-35.3)% = 31.0%.
When randomly choosing one student from the whole school, it is most likely (35.3%) that the student is in the eleventh grade.
Answer:
6. Actual length is 8 mm.
7. 13
8. 4
9. x=12
10. y=4
11. a=-3
12. y=-5
Step-by-step explanation: