Answer:
86%
Step-by-step explanation:
Let g represent the mean mark for the 10 girls in the class. Then the mean mark for the class was ...
10g +20(62%) = 30(70%)
g = 3(.7) -2(.62) . . . . . . . . . divide by 10 and subtract 2(.62)
g = .86 = 86%
The mean mark for girls was 86%.
_____
You can do this in your head if you consider it in terms of deviations from the mean. The second equation above can be rewritten and factored as ...
g = 70% +2(70% -62%)
That is, because there are 2 boys for every girl, the girl's score is above the mean by an amount that is 2 times the amount that the boy's score is below the mean. The boys' score is below by 8%, so the girls' score is above by 16%, so is 86%.
Answer:
g(q) = 
Step-by-step explanation:
Given
- 7q + 12r = 3q - 4r
Rearrange making r the subject
Add 7q to both sides
12r = 10q - 4r ( add 4r to both sides )
16r = 10q ( divide both sides by 16 )
r = 
= , thus
g(q) =
<span>If two angles are supplementary to the same angles, then "Their sum would be equal to 180 degrees"
Hope this helps!</span>
Answer:
5/2
Step-by-step explanation:
duh
Answer:
x = 2.
Step-by-step explanation:
5[3(x + 4) − 2(1 − x)] − x − 15 = 14x + 55
5[3x + 12 - 2 + 2x] - x - 15 = 14x + 55
5[5x + 10] - x - 15 = 14x + 55
25x + 50 - x - 15 = 14x + 55 Now we subtract 14x from both sides:
25x + 50 - x - 15 - 14x = 14x - 14x + 55
10x + 50 - 15 = 55 Now we subtract 50, add 15 to both sides:
10x + 50 - 50 - 15 + 15 = 55 - 50 + 15
10x = 20
x = 2.
