Question

Calculeaza , dupa model
Model : 1004*1003+2*1004-1005*1002=
=1004*(1003+2)-1005*1002=
=1004*1005-1005*1002=
=1005*(1004-1002)=1005*2=2010
a) 7*8+2*7+9*10
b) 37*28+42*37-42*15
c)207*28+207*180-208*206
d)3009*3008-3008*3007-2*3006
e)5010*5009+5009-5011*5008
f)2016*2015+2*2016-2017*2015
va rog frumos!!!!

Answer 1

a)
7*8+2*7+9*10=
7×(8+2)+9×10=
7×10+9×10=
10×(7+9)=
10×16=
160


b)
37*28+42*37-42*15=
37×(28+42)-42×15=
37×70-42×15=
2590-630=
1960


c)
207*28+207*180-208*206=
207×(28+180)-208×206=
207×208-208×206=
208×(207-206)=
208×1=
208


d)
3009*3008-3008*3007-2*3006=
3008×(3009-3007)-2×3006=
3008×2-2×3006=
2×(3008-3006)=
2×2=
4


e)
5010*5009+5009-5011*5008=
5009×(5010+1)-5011×5008=
5009×5011-5011×5008=
5011×(5009-5008)=
5011×1=
5011


f)
2016*2015+2*2016-2017*2015=
2016×(2015+2)-2017×2015=
2016×2017-2017×2015=
2017×(2016-2015)=
2017×1=
2017