Đồng đoàn
150
30
tinh :
A=(-2+15+-29)-(45-1310)+25+620
B=12+122+123+124+...+1210
C=(1+11.3)+(1+12.4)+(1+13.5)+(1+17.9)
1:tim cac so nguyen x,y biet: y=72x+1