9514 1404 393
Answer:
D. 13.8
Step-by-step explanation:
FE being the midsegment means E is the midpoint of BC. The midpoint divides the segment into two equal parts, so BE = EC = 6.9. The length BC is the sum of those parts:
BC = BE +EC = 6.9 +6.9 = 13.8
The length of BC is 13.8 units.
Step-by-step explanation:
–6(x + 5) + 3 = –2(x + 4) – 4x
–6x – 30 + 3 = –2x –8 – 4x
–6x –27 = –6x –8
–6x + 6x = –8 + 27
0 = 19
no solution
The area of the central rectangle = 5 * 3 = 15 ins^2
area of each triangle = 1/2*3*3 = 4.6 ins^2
Total area = 2*4.5 + 15 = 24 ins^2 (answer)
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%.
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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:
1:
Step-by-step explanation:
