91 . 51 + 49 . 163 + 49 . 72
Tính nhanh
91 x 51 + 49 x 163 - 49 x 72
91 x 51 + 49 x 163 - 49 x 72
= 91 x 51 + 49 x ( 163 - 72 )
= 91 x 51 + 49 x 91
= 91 x ( 51 + 49 )
= 91 x 100
= 9100
91x51 + 49x163-49x72
=91x51+49x( 163-72)
=91x51+49x91
=91x(51+49)
=91x100
=9100
91 x 51 + 49 x 163 - 49 x 72
= 91 x 51 + 49 x ( 163 - 72 )
= 91 x 51 + 49 x 91
= 91 x ( 51 + 49 )
= 91 x 100
= 9100
2023 x 14 + 2023 x 83 +97
78 x 31 + 78 x 24 + 78 x 17 + 78 x 22 x 72
371 x 69 + 371 x 14 + 629 x 83
91 x 51 + 49 x 163 - 49 x 72
3 x 12 x 17 + 4 x 9 x 81 + 2 x 6 x 6
42 x 17 + 58 x 83 x 42 x 83 + 42 x 83 + 58 x 17
tính bằng cách hợp lý nhất
`@` `\text {Ans}`
`\downarrow`
`2023 \times 14 + 2023 \times 83+97`
`= 2023 \times (14+83) + 97`
`= 2023 \times 97 + 97`
`= 196231 +97`
`= 196328`
`78 \times 31+78 \times 24+78 \times 17+78 \times 22 \times 72`
`= 78 \times (31+24+17+22 \times 72)`
`= 78 \times (31+24+17+1584)`
`= 78 \times 1656`
`= 129168`
`371 \times 69+371 \times 14+629 \times 83`
`= 371 \times (69+14) + 629 \times 83`
`= 371 \times 83 + 629 \times 83`
`= 83 \times (371+629)`
`= 83 \times 1000`
`= 83000`
`91 \times 51+49 \times 163-49 \times 72`
`= 91 \times 51 + 49 \times (163-72)`
`= 91 \times 51+49 \times 91`
`= 91 \times (51+49)`
`= 91 \times 100`
`= 9100`
`3 \times 12 \times 17 + 4 \times 9 \times 81 + 2 \times 6 \times 6`
`= 9 \times 4 \times 17 + 4 \times 9 \times 81 + 4 \times 9 \times 2`
`= 9 \times 4 \times (17+81+2)`
`= 36 \times 100`
`= 3600`
`42 \times 17 + 58 \times 83 \times 42 \times 83 + 42 \times 83 + 17`
`= 17 \times (42+58) + 42 \times 83 \times (58 \times 83 +1)`
`= 17 \times 100 + 3486 \times 4815`
`= 1700 + 16785090`
`= 16786790`
53.(51+4)+53.(49+91)+53
\(53.\left(51+4\right)+53.\left(49+91\right)+53\\ =53.55+53.140+53.1\\ =53.\left(55+140+1\right)\\ =53.196\\ =10388.\)
\(53\cdot\left(51+4\right)+\left(49+91\right)+53\)
\(=53\cdot55+53\cdot140+53\cdot1\)
\(=53\cdot\left(55+140+1\right)\)
\(=53\cdot196\)
\(=53\cdot\left(200-4\right)\)
\(=53\cdot200+53\cdot4\)
\(=10600-212\)
\(=10388\)
\(53.\left(51+4\right)+53.\left(49+91\right)+53\)
\(=53.55+53.140+53\)
\(=53.\left(55+140+53\right)\)
\(=53.248\)
\(=13144\)
t) 53 . 51 + 4 + 53 . 49 + 91 + 53
\(53.51+4+53.49+91+53\)
\(=53.\left(51+49+1\right)+4+91\)
\(=53.101+4+91\)
\(=5353+4+91\)
\(=5448\)
Bài 1: Tính hợp lý :
1/ -5 + (-37 - 45+51)-(-37+51)
2/ (53-45-49)-(53+45-49)
3/-15+(89+15-72)-(89-72)
-5 + ( -37 - 45 + 51 ) - ( -37 + 51 )
=-5+ -37 - 45 + 51- -37 + 51
=(37+(-37) +(51-(-51) + (45 - (-5)
=0+0+50
=50
MIK MỚI LÀM ĐC PHẦN A)
53 x 51 + 4 + 53 x 49 + 91 + 53
`#3107.101107`
\(\text{53 x 51 + 4 + 53 x 49 + 91 + 53}\)
\(=53\times\left(51+49\right)+\left(4+91+53\right)\\ =53\times100+148\\ =5300+148\\ =5448\)
53 x 51 + 4 + 53 x 49 + 91 + 53
\(53\times51+4+53\times49+91+53\)
\(=53\times\left(51+49\right)+\left(4+53+91\right)\)
\(=53\times100+148\)
\(=5300+148\)
\(=5448\)
Điền > < =
4658 ...... 4668
72 518 ...... 72 189
63 791 ...... 79 163
49 999 ...... 5000
24002 ...... 2400 + 2
6532 ...... 6500 + 30
9300 - 300 ...... 8000 + 1000
8600 ...... 8000 + 600
4658 < 4668
72 518 > 72 189
63 791 < 79 163
49 999 > 5000
24002 > 2400 + 2
6532 > 6500 + 30
9300 - 300 = 8000 + 1000
8600 = 8000 + 600
TÍNH
51.(128+72)+49.(72+128)
(61.32+39.32):32