Solve for an Unknown Variable

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 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.

Solve for y

• A

• B

• C

• D

After dividing by 4 on each side, 2x + 4y = 8 4y = -2x + 8 4 4 4The final equation solved for for y would be ____________.

• y=-2x+2

• y=-½ x +2

• y=-2x+8

• y=-½ x-8

After subtracting 2x from each side, the resulting equation is shown below:

2x + 4y = 8

4y = -2x + 8

The final step to solve for y would be to ____________.

• divide each term by 4

• divide each term by -4

• add 4 to each side

• subtract 4 from each side

After subtracting 2x from each side, the resulting equation is shown below:

2x + 4y = 8

4y = -2x + 8

The final step to solve for y would be ____________.

• divide each term by 4

• divide each term by -4

• add 4 to each side

• subtract 4 from each side

How would you solve the equation 4x = 100?

• Divide 100 by 4

• Subtract 4 from 100

• Add 4 to 100

• Multiply 100 by 4

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