Solving for the Variable Algebra

What branch of mathematics deals with equations with variables?

• Algebra

• Geometry

• Calculus

• Physics

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 100 by 4

• Subtract 4 from 100

• Add 4 to 100

• Multiply 100 by 4

Solve for x: 7x + 7 = 21

• x = 7

• x = 4

• x = 3

• x = 2

Solve for k.... 31 - 3k = 10

• k = 10

• k = -10

• k = -7

• k = 7

What is a variable?

• It's a number 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/are the variable(s)? Choose the best answer.

• x

• y

• =

• Both x and y are variables

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

• y

• 19

• x

• 2

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

• Subtract 11 from 25

• Add 11 to 25

• Divide 25 by 2

• Multiply 25 by 2

Solve for T.

T + 14 = 63

• T = 49

• T = 39

• T = 77