计算1+(2+3)-(4+5)+(6+7)-(8+9)······-(48+49)+50=
问题描述:
计算1+(2+3)-(4+5)+(6+7)-(8+9)······-(48+49)+50=
答
1+(2+3)-(4+5)+(6+7)-(8+9)······-(48+49)+50
=1+48÷4×(-4)+50
=1-48+50
=3