Jesse has a number riddle for his friends. He wants them to guess what number he is thinking of. He tells them that his number can be represented by the x in the equation
6x - 8 = 16
His friends guess {3, 4, 6, 8}. Using substitution, which guess was the correct number?
*
3
4
6
8
Let's solve the equation using each guess:
1. x = 3
6(3) - 8 = 18 - 8 = 10 (which is not 16)
2. x = 4
6(4) - 8 = 24 - 8 = 16 (which is the correct answer)
3. x = 6
6(6) - 8 = 36 - 8 = 28 (which is not 16)
4. x = 8
6(8) - 8 = 48 - 8 = 40 (which is not 16)
Therefore, the correct number Jesse was thinking of is 4.