x2 + 10y + 25 doesn't factor neatly. If that was x2 + 10x + 25, it would factor to (x + 5)(x + 5) or (X + 5)2
The greatest common factor of 10y plus 15 is 5.
10x+10y+100 There is a common 10 in each number. 10(x+y+10)
(5x-9)(2x-1) when factored
(y - 8)(y - 2)
(y - 8)(y - 2)
10y plus 40 equals 50y.
10y2 - 15y2 = -5y2
Clearly, both terms have 5 as a factor. If you divide by 5, you get the other factor:5+10y = 5(1 + 2y)This can't be further factored.
10y = 9y + 4, so y = 4
maximum value of 6y+10y
2(x - 5y)