Answer:
3026
30
Step-by-step explanation: Average sum of the female and male's test score is the sum of expected value of each gender:

Assuming x represents the random male selected and y represents the random female selected:

3026
The average sum of their scores is 3026.
Average difference is the difference between the expected value (mean) of each gender:

1528 - 1498
30
The average difference of their scores is 30.
Replace the x in 7x by (3x + 1):-
(f o g)(x) = 7 * (3x + 1)
= 21x + 7 which is choice D.
Answer:
Step-by-step explanation:
9). -2.2(4 - 1.9x) = 3.3(0.2x - 0.8)
-8.8 + 2.2(1.9x) = 0.66x - 2.64
-8.8 + 4.18x = 0.66x - 2.64
4.18x - 0.66x = 8.8 - 2.64
3.52x = 6.16
x = 1.75
10). 3.2(1 + 2.6x) = 2.4(x - 3.6)
3.2 + 8.32x = 2.4x - 8.64
8.32x - 2.4x = -3.2 - 8.64
5.92x = -11.84
x = 2
11). 4.6(2x - 5.5) = 3.9 + 0.8(1 + 5.5x)
9.2x - 25.3 = 3.9 + 0.8 + 4.4x
9.2x - 25.3 = 4.7 + 4.4x
9.2x - 4.4x = 25.3 + 4.7
4.8x = 30
x = 6.25
12). 0.2(3x + 2.5) - 4.9 = 3.8 - 2.2(x - 5.5)
0.6x + 0.5 - 4.9 = 3.8 - 2.2x + 12.10
0.6x - 4.4 = -2.2x + 15.90
0.6x + 2.2x = 15.90 + 4.4
2.8x = 20.30
x = 7.25
Answer:
D
Step-by-step explanation:
2x < 16 - 6x
Bring the variables to one side
2x < 16 - 6x
+6x +6x
8x < 16
Divide both sides by the coefficient
8x/8 < 16?8
x < 2