Question

tìm x

2012.[x-9]+1=1

165-15[3x+5]=5.9

Answer 1

a)2012(x-9)=1-1

2012(x-9)=0

x-9=0:2012

x-9=0

x=0+9

x=9

b)15(3x+5)=165-45

15(3x+5)=120

3x+5=120:15

3x+5=8

3x=8-5

3x=3

x=3:3

x=1

Answer 2

1) 2012.[ x - 9 ] + 1 = 1

<=> 2012.[ x - 9 ] =  <=> x - 9 = 0 : 2012 <=> x - 9 = 0 => x = 9

2) 165 - 15[ 3x + 5 ] = 5.9

<=>165 - 15[ 3x + 5 ] = 45 <=> 15[ 3x + 5 ] = 120 <=> 3x + 5 = 8 <=> 3x = 3 => x = 1