Step-by-step explanation:
let's look at the full numbers under the square roots when bringing the external factors back in :
sqrt(9×9×2) - sqrt(3×3×7) + sqrt(8) - sqrt(28)
and let's present these numbers as the product of their basic prime factors
sqrt(3×3×3×3×2) - sqrt(3×3×7) + sqrt(2×2×2) - sqrt(2×2×7)
now we see that we have 2 pairs of square roots : 1 pair ends with a factor of 2, and one pair with a factor of 7.
let's combine these
sqrt (3×3×3×3×2) + sqrt(2×2×2) - sqrt(3×3×7) - sqrt (2×2×7)
and now we move the factors of 2 and 7 back out in front (of course, we need to apply the square root on these factors) :
9×sqrt(2) + 2×sqrt(2) - 3×sqrt(7) - 2×sqrt(7) =
= (9+2)×sqrt(2) - (3+2)×sqrt(7) = 11×sqrt(2) - 5×sqrt(7)
and that is the first answer option.
Alright.
So let's say the number of adults is x.
Therefore, the number of boys is 7x + 1.
And then the total amount of girls is 3.5x + 0.5
So then:
x + 7x + 1 + 3.5x + 0.5 = 82
11.5x + 1.5 = 82
11.5x = 80.5
x = 7
So now we can figure out the number of male and female students.
Male students = 7x + 1
7*7 + 1
49 + 1
50
Male Students = 50
Female students = half of 50
50/2 = 25
Female Students = 25
6+5X<21
*********(THE < IS SUPPOSE TO HAVE A LINE UNDER IT)*******
Answer:
≈ 77 cm²
Step-by-step explanation:
The area of the shaded portion is calculated as
area of outer sector - area of inner sector
= (πR² - π r²) × 
( R is the outer radius, r is the inner radius )
= (π × 14² - π × 7² ) × 
= (196π - 49π ) ÷ 6
= 147π ÷ 6
≈ 77 cm² ( nearest whole number )
