12.1 lesson

Multiple Choice

Do Now

Solve the system of equations using the elimination method.

2x +6y = -10

-6x -6y = 30

• (-5,0)

• (5,0)

• (2,6)

Integer Song (row row your boat)

​Replace with sub-header

Same signs add and keep

Different signs subtract

Keep the sign of the bigger number

Then you'll be exact!

Some text here about the topic of discussion

Multiple Choice

-6+10=

• 16

• -4

• 4

Multiple Choice

-8+-4=

• 12

• -12

• 4

Multiple Choice

9+-13=

• -4

• 4

• 22

Multiple Choice

-3+3=

• 0

• 6

• -6

Multiple Choice

20+-27=

• 7

• -7

• 47

​Time to take the integers quiz

No calculators, this is for a grade!

​You Do

• Collect like terms

• Add/Subtract from Variable side

• Divide by the coefficient of the variable

Open Ended

Collect all the X variables to the left side of the equal sign then rewrite the equation on the space provided or on your handout.

Open Ended

Your equations should look like this:

-4x -8 = 4

Now cancel the constant (-8) with addition or subtraction then re-write the equation in the space below or on your handout.

Open Ended

Your equation should look like this:

-4x = 12

Now solve for x and type your answer below.

​The answer is x=-3

You can check your work by substituting the value of x to the equation.

-6(-3) - 8 = -2(-3) + 4

18 - 8 = 6 + 4

10 = 10

​I Do

​You Do

• Substitute the 8 in the y

• Simplify -3(8)

• Add/ subtract from variable side

• Divide by the coefficient of x

• Enter your answer on next slide

Multiple Choice

What is the value of x?

• x=7

• x=-7

• x=4

• x=-28

​I DO

• Identify which variable we can cancel first (y)

• Add the two equations vertically

• Solve for x

​ 6x = 6

​ 6 6

​ X = 1

• Substitute the value of X=1 to one of the original equations

• Simplify

• Solve for Y

​3x + y = 0

3(1) + y =0

3 + y = 0

-3 = -3

y = -3

​You Do

• identify the variable you can cancel first

• Add the remaining terms vertically

• Solve

Multiple Choice

What is the value of X?

• 4

• -1

• 1

Multiple Choice

What is the value of Y?

• 3

• -3

• 6

Poll

What is the solution to the system of equations?

• (-1,3)

• (3,-1)

Open Ended

Do Now

Solve the system by elimination. Remember the solution to the equation should be an ordered pair!

-4x - 2y = -12

4x + 8y = -24

Open Ended

To cancel the variable X, what factor can I multiply to 5 to cancel it with 10?

Open Ended

If we wanted to cancel the variable y, what factor should I multiply to 1 to cancel with -7?

Poll

Time to vote! What variable do you want to cancel?

• x

• y

Open Ended

If you wanted to cancel the x variable, what factor should you multiply by 1 to cancel with -4?

Open Ended

If you wanted to cancel the y variable, what factor would you multiply by -3 to cancel with 9

Open Ended

What is the solution to the system of equations?