Answer:
Step-by-step explanation:
If there are 90 students and the ratio of boys to girls is 3:2, that means 3x+2x=90
Combine like terms: 5x=90
x=18
2x (girls)=36
3x (boys)=54
1/3 of the boys scored full marks, so 54/3=18 boys scored full marks
The number of girls who scored full marks is half of the number who did not score full marks means that 1/3 of the girls scored full marks. 36/3=12, so 12 girls scored full marks.
(I don't know what the question is sorry if it's incorrect but there's not enough information)
Hope this helps!
Answer:
Step-by-step explanation:

He was 21 in 1980,
There are twelve years in between them all so you subtract 36 from 78 and since he was double as old as Nancy, and Manual was the same age as her, you would divide 42 into two parts, Ric and the 10.5 year olds, and Ric would be 21 in 1980.
Answer:
x² - 7x - 18
Step-by-step explanation:
Remember to follow FOIL.
First, multiply the first. (x)(x) = x²
Next, multiply the second. (x)(2) = 2x
Then, multiply the third. (-9)(x) = -9x
Finally, multiply the last. (-9)(2) = -18
Combine like terms: x² + 2x - 9x - 18
x² - 7x - 18
x² - 7x - 18 is your answer.
~
Answer:
2
Step-by-step explanation:
y would be the first number in the equation on the left side of the equal sign. This looks lik the y=mx+b formula, so m, being slope, would be 7, -3 would be x, and b would be 4.