a) (x - 29) - 11 = 0
x - 29 = 0 + 11
x - 29 = 11
x = 29 + 11
x = 40
b) 231 + (321 - x) = 531
231 + 321 - x = 531
552 - x = 531
x = 552 - 531
x = 21
a) (x - 29) - 11 = 0
(x - 29) = 0 + 11
x - 29 = 11
x = 11 + 29
x = 40
b) 231 + (321 - x) = 531
(321 - x) = 531 - 231
321 - x = 300
x = 321 - 300
x = 21
c) (4 . x + 5) : 3 - 121 : 11 = 4
(4 . x + 5) : 3 - 11 = 4
(4 . x + 5) : 3 = 4 + 11
(4 . x + 5) : 3 = 15
(4 . x + 5) = 15 . 3
(4 . x + 5) = 45
4 . x + 5 = 45
4 . x = 45 - 5
4 . x = 40
x = 40 : 4
x = 10
d) 131 . x - 941 = 27 x 23
131 . x - 941 = 621
131 . x = 621 + 941
131 . x = 1562
x = 1562 : 131
x = 11.9236641221
Học tốt!!!
a) (x-29)-11=0
<=> x-29=0+11
<=>x-29=11
<=> x=11+29
<=>x=40
Vậy x=40
b) 231+(321-x)=531
<=> 321-x=531-231
<=> 321-x=300
<=> x =321-300
<=> x=21
Vậy x=21
c) (4.x+5):3-121:11=4
<=>(4.x+5):3-11=4
<=>(4.x+5):3 =4+11
<=>(4.x+5):3 =15
<=> 4.x+5 =15.3
<=> 4.x+5=45
<=> 4.x =45-5
<=> 4.x=40
<=> x=40:4
<=>x=10
Vậy....
d) 131.x-941=27.23
<=> 131.x-941=621
<=> 131.x =621+941
<=> 131.x= 1562
<=> x =1562:131
<=> x=\(\frac{1562}{131}\)
Vậy...