1. Checking Possible Solutions
Chapter 2.4

2. The Equal Sign! 2x + 6 2x + 6 = 10 Expression Equation
The equal sign turns an EXPRESSION into an EQUATION.
2x + 6
2x + 6 = 10
Expression
Equation

3. The Equal Sign is like a …= =
2 = 2
2 = 2
x = 2
x = 2

4. What if I tell you … x = 3 x + 1= 3 x – 3 = 5; x=8
If I tell you that x is 3, am I right?
If I tell you that x is 4, am I right?
If I tell you that x is 3, am I right?
If I tell you that x is 2, am I right?
x + 1= 3
x – 3 = 5; x=8
Here I’m telling you that I think that x is 8. Am I right?

5. Check the given solution
2n = 26; n=12
16 + x = 34; x=18 ? ?
2(12) = 26
= 34 ? ? 24 = 26 34 = 34
No, n=12 is not a solution to the equation.
Yes, x=18 is a solution to the equation.

6. Check the solution 1) x+9 = 12; x=-3 2) 21 – z = -4; z = 25
3) 91 = 7c; c = 13
4) y = -8; y = 32
Is NOT a solution
IS a solution
IS a solution
Is NOT a solution 4