The absolute value of the difference between the time anyone takes and 45 is less than or equal to 8

|t - 45| <= 8 is the correct choice ( the last one)

8 0

3 years ago

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In the expansion of (ax+1)^7 the fifth term is 945x^3 Find the value of a.

Advocard [28]

Answer:

a = 3

Step-by-step explanation:

First start writing out the binomial expansion of $(ax + 1)^7$

$[1^7] + [7C1 * 1^6 *(ax)] + [7C2*1^5*(ax)^2]+[7C3*1^4*(ax)^3]$

as you can see from this, the last bracket will produce our $x^3$ term

$7C3*1^4*a^3x^3 \\35a^3x^3\\35a^3 = 945\\a^3 = 27\\a = 3$

Hope this helps, let me know if you have any questions :)

6 0

3 years ago

The diameter of a pizza is 14 inches. what is the circumference?

algol13

The formula for finding the circumference of a circle is 2πr or πd
So, there are 2 ways to find it.

1) Using the diameter, you would do π x 14.
This will give you 43.9822971503
(round the number to however many dp it says to do :) )

2) Using the radius (half of the diameter), you could do 2π x 7
which will also get you 43.9822971503

5 0

3 years ago