Bonjour
factoriser :
1) 9y²-5y
= y * 9y - y * 5
= y(9y - 5)
2)6y+9
= 3 * 2y + 3 * 3
= 3(2y + 3)
3) (y+4)(y-6)+(-1+y)(y-6)
= (y - 6)(y + 4 - 1 + y)
= (y - 6)(2y + 3)
4) (3y-1)-(3y-1)²
= (3y - 1)(1 - 3y + 1)
= (3y - 1)(-3y + 2)
5) 4-y²
= 2^2 - y^2
= (2 - y)(2 + y)
6) 25-36y²
= 5^2 - (6y)^2
= (5 - 6y)(5 + 6y)
7) (4y-3)²-1
= (4y - 3)^2 - 1^2
= (4y - 3 - 1)(4y - 3 + 1)
= (4y - 4)(4y - 2)
= 4(y - 1) * 2(2y - 1)
= 8(y - 1)(2y - 1)
