7 x 85 + 15 x 17 - 700
= ( 85 + 15 ) x ( 17 - 7 ) x 700
= 100 x 10 x 700
= 1000 x 700
= 700000
Học tốt!!!
Bài làm:
Ta có: \(7.85+15.17-700\)
\(=5\left(7.17+3.17\right)-700\)
\(=5.10.17-700\)
\(=850-700\)
\(=150\)
7.85+15.17-700
=7.5.17+15.17-700
=17.(7.5+15)-700
=17.50-700
=850-700
=150
Hok tốt ! ^^
7*85+15*17-700
=700*(17-7)*(85+15)
=700*10*100
=7000*100
=700000