The following are the ages (years) of 5 people in a room: 12, 20, 22, 22, 23 A person enters the room. The mean age of the 6 people is now 23. What is the age of the person who entered the room?

39

Step-by-step explanation:

12+20+22+22+23=99

new mean=23

23*6=138

138-99=39

system of linear equation

step-by-step explanation:

as given in the data

a= 20 , b= -12

let us suppose that it is a straight line equation

now we know the formula for the system of linear equation

b= ma + c )

here m is slope of a straight line which is equal to formula

m=   (ii)

and here c is a constant

now putting the value of a and b in equation (ii)

m=

m=

putting the value of a,b and m in equation (i) gives us

-12 = + c

-12=-12 + c

adding 12 to both sides

-12 +12 = -12 +12 +c

0 =c

or c=0

as the value of the constant is zero which gives us that it is a linear equation and this order pair satisfies the system of linear equations.