On a I= (x-5)² - (2x-3)²
(x-5)² = a
(2x-3)² = b
I = [(x-5)+(2x-3)] * [(x-5)-(2x-3)]
On a K = 36(2x+1)²-81(x-4)²
K = 6²*(2x+1)²-9² *(x-4)²
a= [6*(2x+1)]²
b² = [9*(x-4)]²
K =[[6*(2x+1)]+[9*(x-4)]*[[6*(2x+1)]-[9*(x-4)]]
On a J = 4(5x+2)² - (2x-6)²
a=[2*(5x-2)]
b=(2x-6)
J = [[2*(5x-2)]+(2x-6)]*[[2*(5x-2)]-(2x-6)]
Voilà
