3x = 9y
9y = 3x
y = 3x/9
y = 1/3x
The slope is 1/3
The volume of a cube with side length equal to x, is
,
thus, the volume of a cube shaped box, whose side length is (5a+4b) is :
,
The volume is already expressed in terms of a and b, but we can expand the expression
, as follows:
![(5a+4b)^{3} =(5a+4b)(5a+4b)^{2}= (5a+4b)[ (5a)^{2}+2(5a)(4b)+ (4b)^{2}]](https://tex.z-dn.net/?f=%285a%2B4b%29%5E%7B3%7D%20%3D%285a%2B4b%29%285a%2B4b%29%5E%7B2%7D%3D%20%285a%2B4b%29%5B%20%285a%29%5E%7B2%7D%2B2%285a%29%284b%29%2B%20%284b%29%5E%7B2%7D%5D)
![=(5a+4b)[ 25a^{2}+40ab+ 16b^{2}]](https://tex.z-dn.net/?f=%3D%285a%2B4b%29%5B%2025a%5E%7B2%7D%2B40ab%2B%2016b%5E%7B2%7D%5D)
![=(5a)[ 25a^{2}+40ab+ 16b^{2}]+(4b)[ 25a^{2}+40ab+ 16b^{2}]](https://tex.z-dn.net/?f=%3D%285a%29%5B%2025a%5E%7B2%7D%2B40ab%2B%2016b%5E%7B2%7D%5D%2B%284b%29%5B%2025a%5E%7B2%7D%2B40ab%2B%2016b%5E%7B2%7D%5D)
Answer:
,
or
The sequence here start out by adding 3 then 5 then 7
we see an increse of 2 to what we are adding so to get the next one we would add 2 to 7 to get 9 then add that to 22 to get 31
Answer:
100 miles Is the correct amswer
Triangular sequence = n(n + 1)/2
If 630 is a triangular number, then:
n(n + 1)/2 = 630
Then n should be a positive whole number if 630 is a triangular number.
n(n + 1)/2 = 630
n(n + 1) = 2*630
n(n + 1) = 1260
n² + n = 1260
n² + n - 1260 = 0
By trial an error note that 1260 = 35 * 36
n² + n - 1260 = 0
Replace n with 36n - 35n
n² + 36n - 35n - 1260 = 0
n(n + 36) - 35(n + 36) = 0
(n + 36)(n - 35) = 0
n + 36 = 0 or n - 35 = 0
n = 0 - 36, or n = 0 + 35
n = -36, or 35
n can not be negative.
n = 35 is valid.
Since n is a positive whole number, that means 630 is a triangular number.
So the answer is True.
