Quiz 1.5 System of Linear Equations

The solution of the system of equations shown in the graph is _____.

Tags

CCSS.8.EE.C.8B

Anika, Grace, and Michael are working on a math problem. They are trying to find the values of two variables in two equations. What does it mean when they decide to solve the system by substitution?

• They try different numbers for the variables until they find a combination that works

• They solve for a variable in one equation, and then plug what it is equal to into the other equation

• They line the equations up and subtract them from each other to eliminate a variable

• They hire a substitute to do their math for them

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

State the working equation of the system below using SUBSTITUTION method:

y = 2x - 1

2x + 2y = 22

Mathematical Equivalence

ON

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Elijah, David, and Daniel are trying to meet up, but they can't seem to find a common location. If they each represent a line in a system of equations, what does it mean if they can't find a common meeting point?

• They are all heading to the same location

• They are all heading in different directions without any intersection

• They will all meet at one specific location

• They are all heading in directions that are perpendicular to each other

Aria, Daniel, and Rohan are working on a math problem. They each come up with a system of equations to solve it. They realize that their systems have infinite solutions. What does this mean about their equations?

• The two equations they each came up with are actually the same line

• The two equations they each came up with are parallel lines

• The two equations they each came up with intersect at one point

• The two equations they each came up with are perpendicular lines

Tags

CCSS.8.EE.C.8A

Aiden and Anika are trying to meet at a point. They start from different locations and move along straight paths. What does it mean if they meet at one point?

• They are actually moving along the same path

• They are moving along parallel paths

• They intersect at one point

• They are moving along perpendicular paths

Answer explanation

Did you get it?

Don't forget that while two perpendicular lines do in fact have one solution, not every system of equations with one solution has two lines that are perpendicular!

What is the first step to solving a system of equations by elimination?

• Make sure that the coefficients one of the variables (x or y) are opposites

• Add the equations together

• Subtract the equations from each other

• Isolate one of the variables

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What is the value of x + y in the system?

• 1

• -5

• 5

• -1

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Arjun and Charlotte are trying to solve a problem. They have two equations representing the number of apples (x) and oranges (y) they have:

2x + y = -12

-4x -2y = 30

Can you help them find a solution?

Tags

CCSS.8.EE.C.8B

Solve by any method

y = x -7

3x -3y = 21

Tags

CCSS.8.EE.C.8B