Question

[pham khanh duyen]

(5*6+11-41)*(1+2+3+..+100)

(2+4+6+...+100)*(11*7-78-1)

20152015*2016-20162016*2015

Answer 1

[nguyễn tuấn thảo]

\(\left(5\times6+11-41\right)\times\left(1+2+3+\cdot\cdot\cdot+100\right)\)

\(=\left(30+11-41\right)\times\left(1+2+\cdot\cdot\cdot+100\right)\)

\(=\left(41-41\right)\times\left(1+2+\cdot\cdot\cdot+100\right)\)

\(=0\times\left(1+2+\cdot\cdot\cdot+100\right)\)

\(=0\)

Answer 2

[nguyễn tuấn thảo]

\(\left(2+4+\cdot\cdot\cdot+100\right)\times\left(11\times7-78+1\right)\)

\(=\left(2+4+\cdot\cdot\cdot+100\right)\times\left(77+1-78\right)\)

\(=\left(2+4+\cdot\cdot\cdot+100\right)\times0\)

\(=0\)