20+4 70+2 10+9 40+4 30+5 наверное
<span>длина вектора АВ будет=</span>√(1^2+(-2)^2+3^2)=√(1+4+9)=√14
83-17=66 20•2=40 66-40=26
(5х + 1) : 3 = (1 + 8) : 5
(5х + 1) : 3 = 9 : 5
(5х + 1) : 3 = 9/5
5х + 1 = 9/5 * 3 = 27/5 = 5 2/5
5х = 5 2/5 - 1 = 4 2/5
х = 4 2/5 : 5 = 22/5 * 1/5 = 22/25
1. х-7=34+28
х-7=62
х=62+7
х=69
2. 52+а=76
а=76+52
а=128