Bạn xem hình

Đáp án:

Giải thích các bước giải:

149:x=24149:x=24 (dư 5)
⇒x=24x149+5⇔x=3576+6=3581⇒x=24x149+5⇔x=3576+6=3581
Vậy x=3581x=3581
d)420:(x:39)=105⇔x:39=420:105=4⇔x=4x39=156420:(x:39)=105⇔x:39=420:105=4⇔x=4x39=156
Vậy x=156x=156
e)480:x+340=420⇔480:x=420−340=80⇔x=480:80=6e)480:x+340=420⇔480:x=420−340=80⇔x=480:80=6
Vậy x=6x=6
g)x7=621⇔x=621x7=2g)x7=621⇔x=621x7=2
Vậy x=2x=2
h)49=8x⇔x=8:49=18h)49=8x⇔x=8:49=18
Vậy x=18x=18
Bài 2:
a)x+1755+30=546⇔x+1755=546−30=516⇔x+175=516x5=2580Vậyx=2580a)x+1755+30=546⇔x+1755=546−30=516⇔x+175=516x5=2580Vậyx=2580
b)45−x=12+118⇔45−x=918+118=1018⇔x=45−1018=1145b)45−x=12+118⇔45−x=918+118=1018⇔x=45−1018=1145
Vậy x=1145x=1145
c)2+x+3+x+x=50⇔5+3x=50⇔3xX=50−3=47⇔x=473c)2+x+3+x+x=50⇔5+3x=50⇔3xX=50−3=47⇔x=473
Vậy x=473x=473
Bài 3:
a)  (X+1)x4=24⇔x+1=24:4=6⇔x=6−1=5(X+1)x4=24⇔x+1=24:4=6⇔x=6−1=5
Vậy x=5x=5
b)(X−36)x5=15x8⇔(X−36)x5=120⇔x−36=120:5=24⇔x=24+26=50b)(X−36)x5=15x8⇔(X−36)x5=120⇔x−36=120:5=24⇔x=24+26=50
Vậy x=50x=50
Bài 4:
a)x−7<3⇔x<3+7=10a)x−7<3⇔x<3+7=10
Vậy x<10x<10
b)x:8<5x<5x8=40b)x:8<5x<5x8=40
Vậy x<40x<40