1,tính
23×(145-17)-145×(23-6)
145×(13-57)+57×(10-146)
Tính hợp lí
1) -145.(13 - 57) + 57.(10 -145)
2) 17.(15 - 16) + 16.( 17- 20)
3) -38.(25 - 4) + 25.(-4 + 38 )
4) 23.(145 - 17) - 145.(23 - 6)
5) 24.(15 - 4) + 4.(24 - 15)
6) 199.(15 - 17) - 199.(-17 + 5)
7) -39.(5 - 99) + 99.(10 - 39)
1) -145.(13 - 57) + 57.(10 -145)
2) 17.(15 - 16) + 16.( 17- 20)
3) -38.(25 - 4) + 25.(-4 + 38 )
4) 23.(145 - 17) - 145.(23 - 6)
5) 24.(15 - 4) + 4.(24 - 15)
6) 199.(15 - 17) - 199.(-17 + 5)
7) -39.(5 - 99) + 99.(10 - 39)
1: \(=-145\cdot13+145\cdot57+57\cdot10-57\cdot145=-1315\)
2: \(=17\cdot15-17\cdot16+16\cdot17-16\cdot20=255-320=-65\)
3: \(=-38\cdot25+38\cdot4-25\cdot4+25\cdot38=13\cdot4=52\)
4: \(=23\cdot145-23\cdot17-145\cdot23+145\cdot6=479\)
5: \(=24\cdot15-24\cdot4+4\cdot24-4\cdot15=360-60=300\)
6: \(=199\left(15-17+17-5\right)=199\cdot10=1990\)
7: \(=-39\cdot5+39\cdot99+99\cdot10-99\cdot39=795\)
1: =−145⋅13+145⋅57+57⋅10−57⋅145=−1315=−145⋅13+145⋅57+57⋅10−57⋅145=−1315
2: =17⋅15−17⋅16+16⋅17−16⋅20=255−320=−65=17⋅15−17⋅16+16⋅17−16⋅20=255−320=−65
3: =−38⋅25+38⋅4−25⋅4+25⋅38=13⋅4=52=−38⋅25+38⋅4−25⋅4+25⋅38=13⋅4=52
4: =23⋅145−23⋅17−145⋅23+145⋅6=479=23⋅145−23⋅17−145⋅23+145⋅6=479
5: =24⋅15−24⋅4+4⋅24−4⋅15=360−60=300=24⋅15−24⋅4+4⋅24−4⋅15=360−60=300
6: =199(15−17+17−5)=199⋅10=1990=199(15−17+17−5)=199⋅10=1990
7: =−39⋅5+39⋅99+99⋅10−99⋅39=795
Tính hợp lí:
73.(8-59)-59.(8-73)159.(18-59)-59.(18-159)-145.(13-57)+57.(10-145)17.(15-16)+16.(17-20)-38.(25-4)+35.(-4+38)23.(145-17)-145.(23-6)199.(15-17)-199.(-17+5)-39.(5-99)+99.(10-39)
1.73.(8-59)-59.(8-73)
=73.8-73.59-59.8-59.73
=73.(59-59)-8.(73-59)
=73.0-8.14
=0-112
=-112
2.159.(18-59)-59.(18 - 159)
=159.18-59.159-59.18-59.159
=159.(59-59)-18.(159-59)
=159.0-18.100
=0-1800
=-1800
Tính giá trị các biểu thức sau (Tính nhanh nếu có thể)
a) (- 17) . 32 + 17 . (- 68) – 17
b) 25 . (34 – 89) + 25 . 89
c) – 145. (13 – 57) + 57. (10 – 145)
a) \(\left(-17\right)\cdot32+17\cdot\left(-68\right)-17\)
\(=17\cdot\left(-32-68-1\right)\)
\(=17\cdot\left(-101\right)\)
\(=17\cdot\left(-100-1\right)\)
\(=-1700-17\)
\(=-1717\)
b) \(25\cdot\left(34-89\right)+25\cdot89\)
\(=25\cdot\left(34-89+89\right)\)
\(=25\cdot34\)
\(=850\)
c) \(-145\cdot\left(13-57\right)+57\cdot\left(10-145\right)\)
\(=-145\cdot13+145\cdot57+57\cdot10-145\cdot57\)
\(=-145\cdot\left(13+57\right)+57\cdot\left(145+10\right)\)
\(=-145\cdot70+57\cdot155\)
\(=-10150+8835\)
\(=-1315\)
`@` `\text {Ans}`
`\downarrow`
`a)`
\((- 17) . 32 + 17 . (- 68) – 17 \)
`= (-17). (32 + 68 + 1) `
`= (-17). 101`
`= -1717`
`b)`
\(25 . (34 – 89) + 25 . 89\)
`= 25. (34 - 89 + 89)`
`= 25. 34`
`= 850`
`c)`
\(– 145. (13 – 57) + 57. (10 – 145)\)
`= (-145). 13 - (-145). 57 + 57.10 + 57. (-145)`
`= (-145). (13 - 57 + 57) + 57.10`
`= (-145). 13 + 570`
`= -1885 + 570 = -1315`
-145(13-57)+57(10-145)
-145 (13-57) + 57(10-145)
17(15-16) + 16(17-20)
-38(25-4)+25(-4+38)
Tính hợp lý giúp mình vs ạ,mình cảm ơn mn nhiều
5. -145.(13 - 57) + 57 (10 - 145)
7. 199.(15 - 17) -199.(-17 + 5)
8. -39.(5 - 99) + 99.(10 - 39)
9. -38.(25 - 4) + 25.(-4 + 38)
bạn ơi sao bạn đổi được hình ảnh đai diện mà mình ko đổi được???
5. -145.(13-57) +57.(10-145)
7. 199.(15-17) -199.(-17+5)
8. -39.(5-99) +99.(10-39)
9. -38.(25-4) + 25.(-4+38)
tính nhanh
-145.(13-17)+57(10-145)
-39*(5-99)+99.(10-39)