Bonjour ;
a.
x(2x + 5) + (3x - 1)(2x + 5)
= (2x + 5)(x + 3x - 1)
= (2x + 5)(4x - 1) .
b.
(2x + 3)(x - 6) - (x - 6)²
= (2x + 3)(x - 6) - (x - 6)(x - 6)
= (x - 6)(2x + 3 - x + 6)
= (x - 6)(x + 9) .
c.
4(3z - 5)² - 2z(3z - 5)
= 4(3z - 5)(3z - 5) - 2z(3z - 5)
= 2(3z - 5) x 2(3z - 5) - 2z(3z - 5)
= 2(3z - 5)(6z - 10) - 2z(3z - 5)
= 2(3z - 5)(6z - 10 - z)
= 2(3z - 5)(5z - 10)
= 2(3z - 5) x 5(z - 2)
= 10(3z - 5)(z - 2) .
d.
(3t - 5)² + (3t - 5)(3t + 5)
= (3t - 5)(3t - 5) + (3t - 5)(3t + 5)
= (3t - 5)(3t - 5 + 3t + 5)
= (3t - 5) x 6t
= 6t(3t - 5) .
