600 is the answer...........
Answer: 6+4x=26, 4x=20
Step-by-step explanation: 6+4x=20 is the initial equation but completely multiplied by two, so you can know without solving that it is equivalent.
If you solve the equation, 2x+3=13 (subtract 3 from both sides)
2x=10 (divide both sides by 2)
x equals 5.
if you plug in 5 as x to 4x=20, you get 20=20, which is a true statement, so this choice is also correct. You could also solve to prove x equals 5 in this equation as well. Divide 20 by 4 and you get x=5.
What do you mean by find?
I don’t know to be honest just ask for help somewhere else’s 123
Answer: 
Step-by-step explanation:
The formula for calculating mean = sum of each data / total number
Let the age of the sixth person be x , then
mean = 23 + 13 + 17 + 12 + 15 + x / 6
That is :
22 = 23 + 13 + 17 + 12 + 15 + x / 6
22 = 
= 22 x 6
