x + 72 = 36
Tính nhanh :
a , 117 x 36 + 117 x 72 - 17 x 72 - 17 x 36
b,408 x 53 - 5 x 204 - 204
117 x 36 + 117 x 72 - 17 x 72 - 17 x 36
= ( 117 - 17 ) x 36 - ( 117 - 17 ) x 72
= 100 x 36 - 100 x 72
= 100 x ( 36 - 72 )
= 100 x -36
= -3600
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408 x 53 - 5 x 204 - 204
= 408 x 53 - 5 x 204 - 204 x 1
= 408 x 53 - ( 5 - 1 ) x 204
= 408 x 53 - 4 x 204
= 21624 - 816
= 20808
tinh nhanh 72 x 19 + 36 x 6 x 10 + 144 x 40 - 72 x 29
`= 72 xx 19 + 36 xx 2 xx3 xx 10 + 72 xx 80 - 72 xx 29`
`= 72 xx(19 + 30 - 29 + 80)`
`= 72 xx 100`
`= 7200`
\(=72.19+36.2.3.10+72.2.40-72.29\)
\(=72.19+72.30+72.80-72.29\)
\(=72.\left(19+30+80-29\right)\)
\(=72.100=7200\)
Tìm x biết:
a, (x + 72) × 4 = 320
b, (x - 56) × 7 = 749
c, (x + 3) × 4 = 36
d, (x - 5) × 6 = 72
36 x 22 x 51/11 x 17 x 72 = ?
\(=\dfrac{36\cdot22\cdot51}{11\cdot17\cdot72}=\dfrac{1}{2}\cdot3\cdot2=3\)
Tính nhanh :
72 x 26 + 36 x 48
Ta có: \(72\cdot26+36\cdot48\)
\(=36\cdot2\cdot26+36\cdot48\)
\(=36\cdot52+36\cdot48\)
\(=36\cdot\left(52+48\right)\)
\(=36\cdot100=3600\)
tính nhanh : 72 x 26 + 36 x 48
Sửa đề:
\(72\times26+26\times28\)
\(=\left(72+28\right)\times26\)
\(=100\times26\)
\(=2600\)
\(72\times26+36\times48=72\times26+26\times48+480=26\times\left(72+48\right)+480=26\times120+480=26\times120+120\times4=120\times\left(26+4\right)=120\times30=3600\)
36 x 5 + 72 x 2 - 216 + 144
36 x 117 x 36 x 43 - 72 x 30 = bnhieu ạ? ghi rõ cách làm cho em luôn ạ. E cảm ơn!
Sửa đề: 36*117-36*43-72*30
=36(117-43-60)
=36*14=504
36 x 48/96 x 72