1: =1-1+5-5+7-7+8-8=0

2: =14-23+5+14-5+23+17

=28+17=45

3: =12-12+9-9+14-44-3=-33

4: =22-8-8-12+4

=22-16-8

=-2

Bài \(1\)

\(1)\) \(1-5+7-8+4-1+5-7+8\)

\(=(1-1)+(5-5)+(7-7)+(8-8)\)

\(=0+0+0+0\)

\(=0\)

\(2)\) \(14-23+(5+14)-(5-23)+17\)

\(=14-23+5+14-5+23+17\)

\(=(14+14)+(23-23)+(5-5)+17\)

\(=28+17\)

\(=45\)

\(3)\) \(12-44+9-3+14-19-9-12\)

\(=(12-12)+(9-9)+(14-44)+3\)

\(=-30+3\)

\(=-33\)

\(4)\) \(22-(4-8+12)+(-8-12+4)\)

\(=22-4+8-12-8-12+4\)

\(=22+(4+4)+(8-8)+(-12-12)\)

\(=22-24\)

\(=-2\)

1+4+5+9+14+.......+60+97

=1+4+5+9+14+23+37+60+97

=5 + 5 + 23 + 23 + 97 + 97

=2 x (5 + 23 + 97)

=250

2 số hạng trước = số sau

quy luat cua chung la 2 so truoc cong lai bang 2 so hang thu ba

1+4+5+9+14+.......+60+97

=1+4+5+9+14+23+37+60+97

=5 + 5 + 23 + 23 + 97 + 97

=2 x (5 + 23 + 97)

=250

A=1+2+4+5+7+8+...+97+98

  =3+9+15+...195 (mỗi số cách nhau 6 đv)

  =33x(195-3):2

  =3168

B=1+4+5+9+14+23+37+60+97

  =247

A = 1+2+4+5+7+8+...+97+98

=(1+98)+(2+97)+...+(49+50)(49 cặp)

=99.49

=4851

B = 1+4+5+9+14+...+60+97

=sai đề

( 98 - 1) : 1+ 1

( 97 - 1) : 1 + 1

Nếu thấy sai thì cậu cũng nên cho tớ đúng 1 cái nhé ! PLEASE! THANK YOU !

\(1+4+5+9+14+...+60+97\)

\(\Rightarrow=1+4+5+9+14+23+37+60+97\)

\(\Rightarrow=5+5+23+23+97+97\)

\(\Rightarrow=2\times\left(5+23+97\right)\)

\(\Rightarrow=2\times125\)

\(\Rightarrow=250\)

k mk nha mí bạn

làm sao mà tính tổng được

1+4+5+9+14+.......+60+97

=1+4+5+9+14+23+37+60+97

=5+5+23+23+97+97

=2x(5+23+97)

=250

1 + 4 + 5 + 9 + 14 + ... + 60 + 97

= 1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97

= (1 + 4) + 5 + (9 + 14) + 23 + (37 + 60) + 97

= 5 + 5 + 23 + 23 + 97 + 97

= 5 x 2 + 23 x 2 + 97 x 2

= 2 x (5 + 23 + 97)

= 2 x 125

= 250

đáp số:250

ai k mk mk sẽ k lại cho ủng hộ mk nha ^_^

1+4+5+9+14+.......+60+97

=1+4+5+9+14+23+37+60+97

=5+5+23+23+97+97

=2x(5+23+97)

=250

250 nha