1.Tìm x , biết :a)35.(x-10)=35b)21.(32-x)=21c)25.(2x.4).12=0d)(x-4):6-5=10e)485-(6.x+60)=5f)315+(135-x)=450g)346+(210-x)=556h)(x-32)-68=0i)274-(9.x+18)=4j)442+(418-x)=860k)107+(210-x)=317l)x-280:35=5.54m)(x-120):35=5n)(x+100)=800o)x.5+10.9=990p)x-120:30=40q)(x+120):20=8r)(x+5).3=300s)x.2+21:3=272.Tính nhanha) 99 - 97 + 95 - 93 + 91 - 89 + ... + 7 - 5 + 3 -1b)47.8 - 27.9 + 47.12 - 27.11c) 1326 +538-326-62d) 2391-147-253e) 8-96+94-92+90-88+...+7-5+3-1f)...
Đọc tiếp
1.Tìm x , biết :
a)35.(x-10)=35
b)21.(32-x)=21
c)25.(2x.4).12=0
d)(x-4):6-5=10
e)485-(6.x+60)=5
f)315+(135-x)=450
g)346+(210-x)=556
h)(x-32)-68=0
i)274-(9.x+18)=4
j)442+(418-x)=860
k)107+(210-x)=317
l)x-280:35=5.54
m)(x-120):35=5
n)(x+100)=800
o)x.5+10.9=990
p)x-120:30=40
q)(x+120):20=8
r)(x+5).3=300
s)x.2+21:3=27
2.Tính nhanh
a) 99 - 97 + 95 - 93 + 91 - 89 + ... + 7 - 5 + 3 -1
b)47.8 - 27.9 + 47.12 - 27.11
c) 1326 +538-326-62
d) 2391-147-253
e) 8-96+94-92+90-88+...+7-5+3-1
f) 24.42-35.24-24.7
g)42.13-22.5+42.22
h)125:4-25:4
i)1159:125-159:125
*Lưu ý : các dấu (.) bằng với dấu nhân nhé
Hơi dài nên mình ko làm
a) 35.(x-10)=35
x-10= 35:35
x-10= 1
x= 1+10
x= 10
b) 21.(32-x) =21
32-x = 21:21
32-x = 1
x= 32-1
x= 31