4-5 solve systems by substitution

What is the first step in solving a system by Substitution?

• Make sure both equations are in standard form.

• Make sure at least one equation is solved for one variable.

• Make sure both equations are in slope-intercept form.

• Make sure both equations can be solved.

Tags

CCSS.HSA.REI.C.6

Solve this system of equations. 
y = 2x + 1
y = 4x - 1

• (1,3)

• (-1,-3)

• (-1,3)

• (3,1)

Tags

CCSS.HSA.REI.C.6

CCSS.8.EE.C.8B

y = -2x + 5
y = 2x - 11

• No Solution

• (0, 0)

• (3, -1)

• (4, -3)

Tags

CCSS.HSA.REI.C.6

CCSS.HSA.REI.D.10

CCSS.HSA.REI.D.11

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

• (-2, -1)

• (1, -2)

• (-2, 1)

• (-1, -2)

Tags

CCSS.HSA.REI.A.1

CCSS.HSA.REI.C.6

Solve:
y = 2x -11
-3y = -6x -15

• (-1.5,-4)

• (1.5,4)

• No solution (parallel lines)

• Infinitely many solutions

Tags

CCSS.HSA.REI.C.6

CCSS.HSA.REI.D.10

CCSS.HSA.REI.D.11

x - 3y = -13
4x + 2y = 4

• (1, 4)

• (-1, -4)

• (-1, 4)

• (1, -4)

Tags

CCSS.HSA.REI.A.1

CCSS.HSA.REI.C.6

y = -2x + 18
y = 8

• (5, 8)

• (-5, 8)

• (2, 8)

• (-2, 8)

Tags

CCSS.HSA.REI.C.6

CCSS.8.EE.C.8B

3x + 2y = 8
-x + y = -11

• (-5,6)

• (6,-11)

• (-6,-5)

• (6,-5)

Tags

CCSS.HSA.REI.C.6

CCSS.8.EE.C.8B

Solve for x and y
3x + 2y = 16
7x + y = 19

• (-2,5)

• (-2,-5)

• (2,-5)

• (2,5)

Tags

CCSS.HSA.REI.C.6

CCSS.8.EE.C.8B

Diego scores 11 more points than Travis.  Together they score 21 points.  How many points did each person score?

• Diego: 11,   Travis: 10

• Diego:  10,  Travis:  11

• Diego: 5,  Travis:  16

• Diego:  16, Travis:  5

Tags

CCSS.8.EE.C.8C