23×50−1531+23×48=23×(48+2)−1531+23×4823×50−1531+23×48=23×(48+2)−1531+23×48 =23×48+23×2−1331+23×48=23×48+3131+23×48=1=23×48+23×2−1331+23×48=23×48+3131+23×48=1 b. 23×50+271+24×49=23×(49+1)+271+(23+1)×4923×50+271+24×49=23×(49+1)+271+(23+1)×49 =23×49+23×1+271+23×49+1×49=23×49+23×1+271+23×49+1×49 =23×49+5023×49+50=1