-20-(25-11+8)+(25-8+20)
=-20-25+11-8+25-8+20
=11-8-8
=-5
=-20-25+11-8+25-8+20
=(-20+20) +(-25+25)+(-8+8)+11
=11
-20-(25-11+8)+(25-8+20)
=-20-25+11-8+25-8+20
=(-20+20)+(-25+25)+11-8-8
=0+0+11-8-8
=11-8-8
=3-8
=-5
mình nhầm dấu nhé
=11+(-8-8)
=11+(-16)
=-5
Thực hiện phép tính bằng cách hợp lí :
a,-20 - (25 -11 +8) + (25 + 8 +20)
b,79.89 - 79.(-11) - 100.79
1) 15 - 98 + 91 - 75 + 98 - 91 - 13
2) 5 - ( 4 - 7 + 12 ) + ( 4 - 7 + 12 ) - 10
3) 20 - ( 25 - 98 + 12 ) + ( 25 - 98 - 72 )
4) - ( 17 - 4 + 13 + | -17 | + 13 )
5) | -16 | - ( 5 - 8 + 7) - ( - 5 ) - 8
6) -20 + ( 3 - 16 + 7 ) - ( 3 - 16 + 7 )
7) 32 - ( 5 - 8 + 32 ) + ( 5 - 8 + 6 )
8) -20 - ( 25 - 11 + 8 ) + ( 25 - 8 + 20 )
97/20 - ( 25/8 - 221/200 )< x < 91/10 - (137/20 - 11/4)
97/20 x ( 25/8 - 221/200 )< x < 91/10 x (137/20 + 11/4)
22/25 x 5/11 - 33/25 : 11/5 + 58/11
8 3/11 - (3 5/7 - 7 8/11 )
1/5 + 7/5 : x = -3/20
5/6x + 325% = 3/2x -30,75
bỏ dấu ngoặc rồi tính
a. 271 – [(-43) + 271 – (-17)]
b. (38 – 29 + 43) – (43 + 38)
c. -20 – (25 – 11 - 8) + (25 – 8 + 20)
a,(100.5^7+5^11:25):(5.5^13:25^2)
b,(3^12+3^11):3^10
c,(2^43+2^4):(2^20+1)
d,(2^22+2^24+2^25):(2^18+2^19+2^20)
e,7.3^9+3^10+51.3^8
a -5/9 + 14/9
b 2/7 + 8/-3
c 9/11+ 5/7+ 20/-11+ 12/25+2/7
Tính tổng:
A=5+6+7+8+...+102
B=2+5+8+11+...+47+50
C=5+10+15+20+25+...+100
Mn bày e gấp với ạ
