MATH de 3eme Merci de bien vouloir me répondre urgent

A =7/3(6x +3) +5/2 (4-2x) 
A = 42x/3 +21/3 + 20/2 -10x/2
A = 42x/3 +21/3 +20/2 -5x
A = 14x +7 +10 -5x
A = 9x +17

B = 4 (1-7y) + (4y -5)(y-1)
B = +4 -28y + ( 4y² -4y -5y +5)
B = +4 -28y +4y² -9y +5
B = +4y² -37y +9

C = 3t(t +1) + (5 +t)(t -2)
C = 3t² +3t +5t -10 +t² -2t
C = t² +6t -10

D = (4k -1)(9 +k) -9k(10 -3k)
D = 36k + 4k² -9 -k -90k +27k²
D = +31k² - 55k -9

E = ( m +2)(8 +3m) 2(1-m)(m-7)
E = (+8m +3m² +16 +6m) 2( m -7 -m² +7m)
E = +3m² +14m +16) 2(-m² +8m -7)
E = +3m² +14m +16 -2m² +16m -14
E = m² +30m +2