Solving systems by graphing and substitution

The solution (x, y) to a system of equations is the point where they...? 

• Run off the graph
• Don't touch
• Intersect
• Exist

Tags

CCSS.HSA.REI.C.6

CCSS.HSA.REI.C.7

CCSS.HSA.REI.D.10

CCSS.HSA.REI.D.11

These two lines intersect at _____.

• (4, -2)
• (4, 2)
• (-2, 4) 
• No solution

Tags

CCSS.HSA.CED.A.2

CCSS.HSA.REI.C.6

CCSS.HSA.REI.D.10

CCSS.HSA.REI.D.11

Solve this system of equations by graphing.

y = 4x - 2

y = -x + 3

• (-2,-1)

• (-1,-2)

• (1,2)

• (2,1)

Tags

CCSS.HSA.CED.A.2

CCSS.HSA.REI.C.6

CCSS.HSA.REI.D.10

CCSS.HSA.REI.D.11

What is the solution to this system?

• (-2, -2)
• (2, -2)
• (-2,2)
• (2, 2)

Tags

CCSS.HSA.REI.C.6

CCSS.HSA.REI.D.10

CCSS.HSA.REI.D.11

The first step in solving using the substitution method is __________.

• get x by itself
• get y by itself
• get either variable by itself
• add the equations together

Tags

CCSS.HSA.REI.C.6

Which variable should you isolate first in the system?

3x + 2y = 10

x - 5y = 18

• The x in the first equation

• The y in the first equation

• The y in the second equation

• The x in the second equation

Tags

CCSS.HSA.REI.C.6

What is the correct first step in solving this system by substitution?

x = 2y +11

-7x -2y = -13

• -7(2y+11) - 2y = -13

• -7x -2(2y +11) = -13

• 2y+11-2y = -13

Tags

CCSS.HSA.REI.C.6

Solve with substitution

x = -3y - 8

x - 2y = -3

• (5, -1)

• (-5, 1)

• (-5,-1)

• (1,-5)

Tags

CCSS.HSA.REI.C.6

Solve the system by substitution

3x - y = 4

x + 2y = 6

• (-2, 2)

• (2, -2)

• (2, 2)

• (-2, -2)

Tags

CCSS.HSA.REI.C.6

What is the best method do you use?

x = 6y − 11

−2x − 3y = −7

• Graphing, because they are both in slope-intercept form

• Substitution because a variable is isolated (solved for)

Tags

CCSS.HSA.REI.C.6

CCSS.HSA.REI.D.11