633 - 124 - 126 + 325
Tính hợp lí
a (221 + 23 - 58 ) - ( 58 + 221 + 23 )
b ( 132 - 325 ) - ( 214 - 428 ) + ( - 221 )
c ( 97 - 146 ) - (124 - 259 ) + ( -227 )
d ( 472 - 534 ) - ( 126 - 224 ) + (-69 )
e ( 68 - 128 ) - ( 247 - 538 ) + ( - 34 )
g ( 149 - 347 ) - ( 226 - 478 ) + ( -67 )
f ( 121 - 345 ) - (125 - 521 ) + ( - 210 )
a (221+23-58)-(58+221+23)
=221+23-58-58-221-23
=(221-221) + (23-23) +(-58-58)
=-116
(132 - 325)-(214-428)+(-211). (97-146)-(124-259)+(-227)
(472-534)-(126-244) +(-69). (68-128)-(247-538+(-34)
(149-347)-(226-478)+(-67). (121-345)-(125-521)+(-210)
1.Chứng minh rằng:122-124+126-...+124n−2-124n+...+122002-122004<0,2
rút gọn phân số sau
a) 90 , 126
b) 625 , 325
126 + (-20) + |124| - (-320) - |-150|
\(126+(-20)+|124|-(-320)-|-150|\\=126-20+124+320+125\\=(320-20)+124+125+126\\=300+375\\=675\)
126+(-20)+|124|-(-320)-|-150|
ko vt lại đề
mà cái này bấm máy tính là ra.........
\(126+\left(-20\right)+|124|-\left(-320\right)-|-150|\)
\(=126-20+124+320-150\)
\(=400\)
126 + ( - 20 ) + | 124 | - ( - 320 ) - | - 150 |
= 126 + ( - 20 ) + 124 - ( - 320 ) - 150
= ( 126 + ( - 20 ) ) + 124 - ( - 320 ) - 150
= 106 + 124 - ( - 320 ) - 150
=( 106 + 124 ) - ( - 320 ) -150
= 230 - ( - 320 ) - 150
= ( 230 - ( - 320 ) ) -150
= 550 - 150
= 400
\(=100+124+320-150\)
\(=224+320-150\)
\(=544-150\)
\(=394\)
126 + (-20) + /124/ - (-320) - /-150/
=126 + (-20) + 124 - (-320) - 15
= 106 + 124 - (-320) - 15
= 230 - (-320) -15
= 230 + 320 - 15
= 550 - 15
= 535