Question

the mean of 7,9,x+3,12,2x-1,3 is is 9 find the value of x

Answer 1

7+9+(x+3)+12+(2x-1)+3/6=9
31+(x+3)+(2x-1)=9
x+3+2x-1=9-31
3x+2=22
3x=22+2
3x=24
x=24/3
x=8