Question

calculati in doua moduri: a) 50x(27+3); b) 14x 49+71x14; c) 17x7+64x7+7x119 ; d) 450x21+550x21-2 100; e) 736x 17+200x17

Answer 1

a)50(27+3)=50*27+50*3=1350+150=1500
  50(27+3)=50*30=1500

b)14*49+71*14=686+994=1680
   14*49+71*14=14(49+71)=14*120=1680

c)17*7+64*7+7*119=119+448+833=1400
17*7+64*7+7*119=7(17+64+119)=7*200=1400

d)450*21+550*21-2100=9450+11550-2100=18900
  450*21+550*21-2100=21(450+550-100)=21*900=18900]

e)736*17+200*17=12512+3400=15912
  736*17+200*17=17(736+200)=17*936=15912