Sagot :
A= 3(2y-6)6(3-5y)
A= 6y-18+18-30y
A= - 24y
B=(5-2y)-(-3y+7)
B= 5-2y+3y-7
B= y-2
C=4(6+z)+(z-3)(2-z)
C=24+4z+2z-z(aucarré)-6+3z
C=-z(aucarré)+9z+18
A = 6y-18 +3+5y = 11y -15
B = 5-2y+3y-7 = y-2
C = 24+4z +( 2z-z²-6+3z) = 24+4z+2z-z²-6+3z
= -z²+9z+18
D = 6t²+4t-15t-10-t²+6
= 5t²-11t-4