<em>Denote x2 by y.
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<em>(x2-3)7=(y-3)7
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<em>This is a binomial expansion in y, and you want the coefficient of y4 because y4=x8
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<em>You have 7 terms of (y-3) in (y-3)7. To get the fourth power of y, you need to choose y from four of the terms. The number of ways you can do this is the combinations of 7 things taken 4 at a time. This is:
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<em>7!/(4!3!)=35</em>
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<em>So, the coefficient of x8 in the given expansion will be 210.</em>
<em>HOPE IT HELPS</em>
<em>THANK YOU </em>
Answer: square root of 3/2 seconds
Step-by-step explanation:
h=-16x²+24
Set the height to be 0
0=-16x²+24
-24=-16x²
24=16x²
24/16=x²
x²=3/2
x= square root of 3/2
Answer:
12.6
Step-by-step explanation:
If 21 divided by 5 is 4.2, you should multiply 3 by 4.2 you'll then get 12.6. to double check, do 5 divided by 3, which is 1.67, and 21 divided by 12.6 is also 1.67. so side OP is 12.6! :)
12 is 20% of 60 because 12/60 = 0.2.
Robbie bought the smallest amount. Let's use x for that amount.
Let's use n for amount that each following customer increases.
We have:
Robbie=x
Cameron=x+n
Louis=x+n+n
Tom=x+n+n+n
Charlie=x+n+n+n+n
We know that they bought total of 60 scones.
Robbie + Cameron + Louis + Tom + Charlie = 60
x + x+n + x+n+n + x+n+n+n + x+n+n+n+n = 60
5x + 10n = 60 /:5
x + 2n = 12
We are also given this information:
(Robbie + Cameron) = 3/7 * (Louis + Tom + Charlie)
We insert the equations from above:
(x + x+n) = 3/7 * (x+n+n + x+n+n+n + x+n+n+n+n)
2x + n = 3/7 * (3x + 9n) /*7
14x + 7n = 3* (3x + 9n)
14x +7n = 9x + 27n
We take everything on the left side.
14x + 7n - 9x - 27n = 0
5x - 20n = 0/:5
x - 4n = 0
Now we have two equations:
x + 2n = 12
x - 4n = 0
We solve second one for x and insert it into first one.
x + 2n = 12
x = 4n
4n + 2n =12
6n = 12 /:6
n = 2
x=4*2
x=8
Now we can solve for the amount for each customer.
Robbie=x = 8
Cameron=x+n = 8 + 2 = 10
Louis=x+n+n = 8 + 2 + 2 = 12
Tom=x+n+n+n = 8 + 2 + 2 + 2 = 14
Charlie=x+n+n+n+n = 8 + 2 + 2 + 2 + 2 = 16
