Plugging Into Equations

Solve the following systems of equations using substitution:

x = 6

y = 2x - 3

• (6, 6)

• (6, 9)

• (9, 6)

• (9, 9)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve the system by substitution.
 
5x + 4y= −14
y =  −7x  −  15 

• (-2, -1)

• (1, -2)

• (-2, 1)

• (-1, -2)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve the system of equations using substitution:
x = -1
y = 3x + 2

• (1, 1)

• (2, -1)

• (-1, -1)

• (-1, 2)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

At what point would the following lines intersect at (use graph paper to help):

y=-3x+2

y=2x-3

• (1,-1)

• (2,3)

• (-3,5)

• (2,6)

Tags

CCSS.8.EE.C.8B

At what point would the following lines intersect at (use graph paper to help): 2y+x=14 y=3x

• (1,-1)

• (2,3)

• (-3,5)

• (2,6)

Tags

CCSS.8.EE.C.8B

At what point would the following lines intersect at (use substitution to solve): 2y=3x+12 y=5x-1

• (2,9)

• (-1,-2)

• (-10,5)

• (2,2)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Sam owns a pet store. He bought 12 bags of dog food and 8 bags of cat food for $101. Two weeks later, Sam bought 9 bags of dog food and 11 bags of cat food for $99.50.

Select the system of equations below that fits this situation best:

• 12d+8c=$99.50

  12d+11c=$101

• 12d+8c=$101

  12d+11c=$99.50

• 20dc=$101

  20dc=$99.50

• 12c-8d=$101

  12c-11d=$99.50

Tags

CCSS.8.EE.C.8C

How do we solve systems of equations using Substitution?

• Isolating a variable in one equation and plugging it into the other equation.

• "getting rid" of a variable in order to solve for the other variable

• Each linear equation is graphed on the same graph. The point of intersection between the two graphs is the solution.

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

At what point would the following lines intersect at (use elimination to solve): 4x-2y=4 2x+y=6

• (2,9)

• (-1,-2)

• (-10,5)

• (2,2)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Which equation would NOT have a solution of (2,6)?

Select ALL that apply

Try plugging the x into the equation and see if the answer is 6

• y= 2x+10

• y=3x-6