When you multiply fractions you want to make them a mixed number then multiply the two top numbers together and then the bottom two together. Basically 6 2/3 would become 20/3 x 5/6... then multiply 5 and 20 together and 3 and 6 together to get 100/18... simplify from there.
B = 2 + 2H
A = 20 ft^2
H = H
Since the Area of a Triangle is Base * Height then the formula should be:
A = BH
20 = H(2+2H)
20 = 2H^2 + 2H
0 = 2H^2 + 2H - 20
Find the zeros of the quadratic equation through substituting the values of a,b, and c. You will get the zeros of x = 2.7 and -3.7. The only thing that would make sense is you use the x=2.7 because there are no negative heights.
Since b = 2h+2
b= 2(2.7) + 2
b= 5.4 + 2
b=7.4
I don't know where you got 4 and 10, but what I got is different.
Answer:
At least 7 girls: 0.5^7 OR 0.0078125
At least 8 girls: 0.5^8 OR 0.00390625
It would be $20.40 because 20% off of $28.00 is $22.4 - $2.00= $20.40