5839:87 =?
Tìm y:
a, y + 847 x 2 = 1953 - 74 b, y : (7 x 18) = 5839 + 8591
Tìm y:
\(a,y+847\times2=1953-74\\ y+847\times2=1879\\ y+1694=1897\\ y=1897-1694\\ y=185\\ b,y:\left(7\times18\right)=5839+8591\\ y:126=14430\\ y=14430\times126\\ y=1818180.\)
a/ y + 847 x 2 = 1953 - 74
y + 1694 = 1879
y = 1879 - 1694
y = 185
b/y : (7 x 18) = 5839 + 8591
y : 126 = 14430
y = 14430 x 126
y = 1818180
#AvoidMe
a. y + 847 x 2 = 1953 - 74
y + 1694 = 1879
y = 1879 - 1694
y = 185
b. y : (7 x 18) = 5839 + 8591
y : 126 = 14430
y = 14430 x 126
y = 1818180
tinh nhanh :87*1000-87*900+87*9+87*11-87*20+87*80-87*60-87*20
=87*(1000-900+9+11-20+80-60-20)
=87*100=8700
So sánh
a) 87.(-20) và |87.(-20)|
b) 87.(-20) và 87.(-20)
c) 87.(-20) và -|-87.20|
a ) 87 . ( − 2 0 ) < | 87 . ( − 2 0 ) |
b ) 87 . ( − 2 0 ) = 87 . ( − 2 0 )
c ) 87 . ( − 2 0 ) = − | − 87 . 2 0 |
tính nhanh:
a)-65.(87-17) - 87.(17-65)
b)87.(13-18) - 13.(87+18)
Tính nhanh:
92 x 87 + 207 x 87 + 87
92 x 87 + 207 x 87 + 87 = 87 x ( 92 + 207 + 1 )
= 87 x 300
= 26100
92 x 87 + 207 x 87 + 87
= 87 x ( 92 + 207 + 1 )
= 97 x 300
= ( 100 - 3 ) x 300
= 100 x 300 - 3 x 300
= 30000 - 900
= 29100
92 x 87 + 207 x 87 + 87
= 87 x ( 92 + 207 + 1 )
= 87 x 300
= 87 x 3 x 100
= 261 x 100
= 26100
Tính (-2)+ (-87)+ (-18)+ 87
(-2) + (-87) + (-18) + 87 = [(-2) + (-18)] + [(-87) + 87]= -20
87-17.(-65)+(-87).(17-65)
-65*(87-17)-87*(17-65)
=-65.87+65.17-87.17+65.87=
=17(65-87)=-17.22
-65 . ( 87 -17 ) -87 . ( 17 - 65 )
-65 . ( 87 -17 ) -87 . ( 17 - 65 )
=(-65).70-87.(-48)
=(-4550)-(-4176)
=(-374)
\(-65.\left(87-17\right)-87.\left(17-65\right)\)
\(=-65.70-87.\left(-48\right)\)
\(=\left(-4550\right)-\left(-4176\right)=-374\)