Question

Вычислите более рациональным способом8,3×7+4,5×7+1,7×7+5,5×70,85×4+0,73×5+0.15×4+0,27×55.25×2+6,31×3+2×0.75+3×0,69

Answer 1

8,3×7+4,5×7+1,7×7+5,5×7=7*(8.3+1.7)+7*(4.5+5.5)=7*10+7*10=70+70=140

0,85×4+0,73×5+0.15×4+0,27×5=(0.85+0.15)*4+(0.73+0.27)*5=1*4+1*5=4+5=9

5.25×2+6,31×3+2×0.75+3×0,69=(5.25+0.75)*2+(6.31+0.69)*3=6*2+7*3=12+21=33