1.3.3.html                              by Meg Cheng-Campbell                      Per. 1

 

®When you solve an equation, know the 2 special cases for:

No Answer and All real numbers. 

 

     -Graphically, it has to do with parallel lines and lines that are the exact same line.

 

     -When you solve Algebraically, you get either an untrue statement like 2=5 or one that is true like 4=4. 

 

 

Result of Equation:

®

Possible Answer

2=5

®

No Solution (parallel lines)

4=4

®

All real numbers (same line)

 

 

-If the result of a linear equation does not balance our (ex: 7=2) then there is “no solution”

-If the result balances out correctly (ex: 1=1) then the answer is “all real numbers”

 

Example #1:  3a+2=3a+3

a)      Solve Algebraically:

3a+2=3a+3                        subtract 2 from both sides

3a=3a+1                            subtract 3a from both sides

0¹1

Answer = No Solution

 

b)      Solve Graphically: 

1è graph both sides of the original problem separately

2è notice that they are parallel and therefore the answer is “No Solution”

 

 

 

Example #2:   -3+4y+6=-4y+8y+3

a)      Solve Algebraically:

-3+4y+6=-4y+8y+3           add 3 to both sides

4y+6=-4y+8y+3+3            add 3+3

4y+6=-4y+8y+6                add 4y to both sides

4y+4y+6=8y+6                  add 4y+4y

8y+6=8y+6                        subtract 8y from both sides

6=6

Answer = All Real Numbers

 

b)      Solve Graphically:

1è graph both sides of the original problem separately

2è notice that they are the same line and therefore the answer is “All Real Numbers”

              Two lines on top of each other

 

 

 

Now you try:

Solve algebraically or graphically

  1. 5y+25=20+5y+2
  2. 8y+6=8y+6
  3. 15n+6=21
  4. 2x-5=4x+15-2x
  5. 3(1-2)-4y=2(2y-4y)-3