Bonsoir,
On a : g(x) = (2x-3)/(x+1)
1) g(0) = (2×0-3)/(0+1) = -3/1 = -3
g(-5/7) = [2×(-5/7)-3]/[(-5/7)+1] = [(-10/7)-21/7]/[(-5/7)+(7/7)] = (-31/7)/2/7 = -31/7 × 7/2 = -31/2 = -15,5
2) g(-1+√5) = [2×(-1+√5)-3] / [-1+√5+1] = (-2+2√5-3) / √5 = (-5+2√5) / √5 = √5×(-5+2√5) / (√5×√5) = (10-5√5)/5