Answer:
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Step-by-step explanation:
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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.
3(2-y) + y = 4.50
6 - 3y + y = 4.50
- 2y = -1.5
y = 0.75
3x + y = 4.50
3x + 0.75 = 4.50
3x = 3.75
x = 1.25
answer
x = 1.25 and y = 0.75
cost of one lemonade = 75 cents
500 at 40 each = £20000
To make a profit he needs to make more than £20000
20 broke so he sold 500-20 = 480 at 45 each.
480 x 45 = 21600
Profit = 21600 -20000 = 1600
His profit was £1,600
Total number of marbles = 5 + 8 + 7 = 20
Total number of non-red marbles = 5 + 7 = 12
P(not red) = 12/20 = 3/5
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Answer: 3/5
