Question

Answer 1

Bài 3: 

a: =>x-7=0

=>x=7

b; =>5(x+2)=50

=>x+2=10

=>x=8

c: =>6(2x+8)=60

=>2x+8=10

=>2x=2

=>x=2

d: =>3(3x+9)=90

=>3x+9=30

=>3x=21

=>x=7

Answer 2

a,=>x-7=0

=>x=7

b; =>5(x+2)=50

=>x+2=10

=>x=8

c: =>6(2x+8)=60

=>2x+8=10

=>2x=2

=>x=2

d: =>3(3x+9)=90

=>3x+9=30

=>3x=21

=>x=7