Cogito
Integrated Math 1 · Chapter 3 · Lesson 1
Solving Systems by Graphing and Substitution
Where two conditions meet.
12 problems · about 21 minutes · A-REI.C.6
Figure — use these to answer the problems
Warm Up
Straightforward practice. Get the method working first.
5 problemsy = 2x and y = x + 5. What is x?
AnswerWhat does a solution to a system mean graphically?
- The point where the lines cross.
- Where each line meets the y-axis.
y = x and y = 4. What is x?
Answery = 3x and y = x + 4. What is x?
AnswerSame system. What is y?
Answer
Build It Up
The same ideas with more to keep track of.
3 problemsy = 2x + 3 and y = 2x + 7. How many solutions?
Answery = 5x − 1 and 2y = 10x − 2. How many solutions?
Answerx + y = 10 and x − y = 2. What is x?
Answer
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
4 problemsMatch each graph situation with the number of solutions.
Draw a line from each item on the left to its match on the right.
- Lines cross once
- Parallel lines
- Identical lines
- Exactly one solution
- No solution
- Infinitely many solutions
y = 4x and y = 2x + 6. What is x?
AnswerThe Substitution
y = 2x + 1 and 3x + y = 11. What is x?
AnswerThe Other Half
Same system. What is y?
Answer