Solving Equations for a Variable

What is a variable?

• It's a number in an equation.

• A letter representing an unknown number in an equation.

• The symbols in an equation that aren't letters or numbers.

• Any equation with an equals sign.

In the equation 2x + 3y = 19, what is the variable? Choose the best answer.

• x

• y

• =

• Both x and y are variables

What branch of mathematics deals with equations with variable?

• Algebra

• Geometry

• Calculus

• Physics

Which symbol is present in every equation?

• x

• +

• -

• =

How do we figure out the value of a variable?

• Add up all the numbers in the equation.

• Multiply the variable by itself.

• Isolate the variable on one side of the equals sign.

• A variable has no set value.

How would you solve the equation 4x = 100?

• Divide each side by 4.

• Subtract 4 from each side.

• Add 4 to each side.

• Multiply each side by 4.

In the equation 2x + 3y = 19, what is the constant?

• Y

• 19

• X

• 2

Solve for x: 7x + 7 = 21

• x = 7

• x = 4

• x = 3

• x = 2

What is the first step in solving the equation 2y - 11 = 25?

• Subtract 11 from both sides.

• Add 11 to both sides.

• Divide both sides by 2.

• Multiply both sides by 2.

Solve for k: 31 - 3k = 10

• k = 10

• k = -10

• k = -7

• k = 7