Вычислите рациональным способом:

1) 8.3*7+4.5*7+1.7*7+5.5*7=

2) 0.85*4+0.73*5+0.15*4+0.27*5=

3) 5.25*2+6.31*3+2*0.75+3*0.69=

4) 9.75*10+0.07*100+0.25*10+0.03*100=

1) 8.3*7+4.5*7+1.7*7+5.5*7 = 7 * (8.3+4.5+1.7+5.5) = 7 * (10+10) = 140

2) 0.85*4+0.73*5+0.15*4+0.27*5 = 4 * (0.85 + 0.15) + 5 * (0.73+0.27) = 4+5 = 9

3) 5.25*2+6.31*3+2*0.75+3*0.69 = 2 * (5.25+0.75) + 3 * (6.31+0.69) = 2*6 + 3*7 = 33

4) 9.75*10+0.07*100+0.25*10+0.03*100 = 10 * (9.75+0.25) + 100 * (0.07+0.03) = 100 + 10 = 110