Explications étape par étape
B = 8 ( 7 - x ) - ( x - 4 )
B = 56 - 8x - x + 4
B = - 9x + 60
C = 5 ( 4 + t ) - 4 ( 7 + t )
C = 20 + 5t - 28 - 4t
C = t - 8
D = ( x + 2 )( x + 3 ) + 6 ( x + 5 )
D = x² + 3x + 2x + 6 + 6x + 30
D = x² + 11x + 36
E = ( b + 2 )( 5 + b ) - ( 7 - b )
E = 5b + b² + 10 + 2b - 7 + b
E = b² + 8b + 3
F = 5 ( t + 2 ) + ( 5 + t )( 6 + 2t )
F = 5t + 10 + 30 + 10t + 6t + 2t²
F = 2t² + 21t + 40