bonsoir,
A = 7/3 - 5/7 x 7/9
A = 7/3 - 35/63
A = 147/63 - 35/63 = 112/63 = 16/9
C = ( 1/4 - 1 )²
C = ( 1/4 - 4/4 )²
C = - 3/4 ²
C = 9/16
16/9 x 9/16 = 1
g(x) =[ ( x - 1) / 5 ] - 4
g (1/3) = [ ( 1/3 - 1)/5] - 4
g (1/3) = [(1/3 - 3/3)/5 ] - 4
g (1/3) = [ - 2/3 x 1/5) - 4
g ( 1/3 ) = - 2/15 - 4 = - 2/15 - 60/15 = - 62/15