Вычислите рациональным способом

1) 147*85+53*60+147*15+53*40

2) 275*32+725*28+275*19+725*22

3) 326*67+174*29+326*33+174*71

147*85 + 53*60 + 147*15 + 53*40 =

= 147 * (85+15) + 53 * (60+40) =

= 147*100 + 53*100=

= 100 * (147+53) = 100*200=

= 20000

275*32 + 725*28 + 275*19 + 725 * 22=

= 275 * (32+19) + 725 * (28+22) =

= 275 * 51 + 725 * 50 =

= 275 * 50 + 275*1 + 725*50=

= 50 * (275+725) + 275 =

= 50*1000 + 275 =

= 50000 + 275=50275

326 * 67 + 174 * 29 + 326 * 33 + 174 * 71 =

= 326 * (67+33) + 174 * (29+71) =

= 326*100 + 174*100=

= 100 * (326+174) =

= 100*500 = 50000