1)4/5 + 2 1/7 = 4/5 + 15/7 =(4 × 7 + 15 × 5)/35 = 28/35 + 75/35 = 103/35 = 2 33/35
2)2 33/35 + 1 1/5 = 103/35 + 6/5 =(103 × 1 + 6 × 7)/35 = 103/35 + 42/35 = 145/35 = 29/7 = 4 1/73)4 1/7 + 3 6/7 = 29/7 + 27/7 = 56/7 = 8
ответ 8
∫sinxcosxdx = ∫0,5sin2xdx = ∫0,25sin2xd(2x) = -0,25cos2x + C
((76+65)(76²-76*65+65²))/141 -76*65=76²-2*76*65+65²=(76-65)²=11²=121
Приводим к общему знаменателю
0,6 0,66 5/8=0,625
0,66 0,625 0,6