\(47\left(23+50\right)-23\left(47+50\right)=47.23+47.50-23.47-23.50=50\left(47-23\right)=1200\)
\(85\left(35-47\right)-35\left(85-27\right)=85.35-85.47-85.35+35.27=35.27-85.47=-3050\)
tính hợp lí
a)29.(85-47)+85.(47-29)
b)47.(23+50)-23.(47+50)
tính hợp lí
a,85.(35-27)-35.(85-27)
b,47.(45-15)-47.(45+15)
Tính hợp lí:
a. -29.(85-47)-85.(47-29)
b. 37.(29-23)-29.(37-23)
c. 5.2004-1002.(-10)+40.501
tính một cách hợp lý :
21 . 35 - 3 . 25 . 7
77 - 11 ( 30 + 7 )
85 ( 35 - 27 ) - 35 ( 85 - 27 )
47 ( 45 - 15 ) - 47 ( 45 + 15 )
tính nhanh:
a) 85.(35-27) - 35.(85-27) =
b) 47.(45-15) - 47.(45+15) =
tính hợp lý
c1, -56+8(11+7)
c2, 47(23+50)-23(47+50)
c3, 85(47-29)+29(85-47)
c4, (-16)(-25)(-12)
c5, -19(16-25)+19(25-4)
c6, 11(16+24)+24(11-16)
c7, 29(85-47)-23(15-29)
c8, 15(23-29)+23(15-29)
c9, 13(55-29)-55(13-29)
c10, 37(27+25)+72(-25)
c11, (-216).68+32(-312)
c12, 44(-50)-50.56
c13, -69(-4).2-3(-7)(-2)
c14, 25.11.(-15)-50.15(-5)
c15, 47.69+31.(-47)
4. Tính. a) (-35) + 23 – (-35) – 47 b) 24 – (-136) – (-70) + 15 + (-115) c) 37 – (-43) + (-85) – (-30) + 15.
77-11.(30+7)
85.(35-27)-35.(85-27)
47.(45-15)-47.(45+15)
tinh nhanh
a. 47.[23+50]-23.[47+50]
b,29.[85-47]+85.[47-29]
c,37.90-37.[-10]
d,15.12-3.5.10
e,29.[19-13]-19.[29-13]
f,33.[17-5]-17.[33-5]
g,54-6.[17+9]
h,1000+[-570]+2341+[-430]
