A rendre demain aidez moi svp

A: 5xt+5x3+2x3t+2x4-(5t-3)
A:5t+15+6t+8-5t+3
A:6t+26

B:3yx2+3yx5y-(4x1-4x2y)+3y[au carré]-5y+3
B:6y+15y[au carré]-4-8y+3y[au carré]-5y+3
B: -7y+18y[au carré]-1

C:4x x 3x + 4x x 5-1x3x-1x5-(x-7)
C:20x[au carré]+16x+2