Expressions and Variables - What is a Variable - ALGEBRA I

The video tutorial introduces the concept of variables in math, explaining their role as placeholders for unknown numbers. It uses the example of solving the equation 2x + 3 = 15 to demonstrate how to find the value of a variable. The tutorial concludes by reinforcing the idea that variables represent unknowns in mathematical expressions.

Why are letters used in math equations alongside numbers?

• To make equations look more complex

• To represent unknown values

• To replace numbers permanently

• To confuse students

In the equation 2x + 3 = 15, what is the first step to solve for x?

• Multiply both sides by 2

• Subtract 3 from both sides

• Add 3 to both sides

• Divide both sides by 2

After subtracting 3 from both sides in the equation 2x + 3 = 15, what is the next step?

• Add 3 to both sides

• Subtract 2 from both sides

• Multiply both sides by 2

• Divide both sides by 2

What does the variable x represent in the equation 2x + 3 = 15 after solving it?

• x is 3

• x is 9

• x is 12

• x is 6

What is a variable in math?

• A placeholder for an unknown value

• A type of equation

• A mathematical operation

• A fixed number