The sum of cubes is given as:
a³ + b³ = (a + b)(a² - ab + b²)
Example for the sum of cubes:
64x³+y³ ⇒ This is the sum of cubes because each term; 64, x³, and y³ are cube numbers
By writing each term as an expression of cube numbers, we have:
(4x)³ + (y)³ ⇒ 64 is 4³
Use the factorization of the sum of cubes, we have:
(4x + y) ( (4x)²- 4xy + y²)
(4x + y) (16x² - 4xy + y²)
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The difference of cubes can be factorized as:
(x³ - y³) = (x - y)(x² + xy + y²)
Example
(125x³ - 8y³) = (5x - 2y) ((5x)² + (5x)(2y) + (2y)²)
= (5x - 2y) (25x² + 10xy + 4y²)
So he has to read 500 and he already read 260 500 - 260 = 240. 240 divided by 30 equals 8. So the answer will be 8 days
I hope this helps you
length w+5
width w
26=2 (w+5+w)
13=2w+5
2w=8
w=4
length =4+5=9
So.... notice the picture below
now, we know what the "height" or "altitude" is
now, we also know the perimeter is 18cm
so, k + k + b = 18
or 2k + b = 18
thus

so... one can say that

and you can simplify it if you wish.. not sure you have to