svp de l'aide j'arrive pas à comprendre c'est l'ex 74 svp ignorez pas

a = 2(3x +1) + 2x = 6x +2 +2x = 8x +2

b = 10y + 4 ( 3-2y) =10y +12 -8y = 2y +12

c  = 5 (2+2x) -3x = 10 +10x -3x = 7x + 10

d = 2 (2x +3 ) + 3 ( 2 +3x) = 4x +6 +6 +9x = 13x+12

2(3x+ 1) + 2x = 6x + 2 + 2x = 8x + 4
10y + 4( 3-2y ) =10y + 12 - 8y = 2y + 12
5(2 + 2x ) - 3x = 10 + 10x - 3x = 7x + 10
2(2x+3) + 3(2 + 3x) = 4x + 6 + 6 +9x = 13x + 12