MATH - SCIENCE INTEGRATION

bullet1 SOLVING ONE STEP EQUATIONS

bullet2 Multiplication

ax = b
To solve multiplication equations you have to divide both sides of the equation by the number you are multiplying the variable by.


bullet3 Example 1

3x = 21
 
  Solve: Divide both sides of the equation by 3 (not 3x just 3)
              3x  =  21
               3         3
 
Solution:  Since 3/3 is 1 you have 1x, which is writen as just x,
                      on the right handside of the =.
                   And 21/3 = 7 you have 7 on the left hand side of the =.
                  x = 7
 
 Check: Substitute 7 in for x in the original equation 3x = 21
                3(7) = 21 and 21 = 21 so 7 is the answer to the equation.


bullet3 Example 2

- 4.79 x = 8.21
 
Solve: Divide both sides of the equation by - 4.79
                    (not - 4.79x just - 4.79)
               - 4.79 x  =  8.21
                - 4.79        - 4.79
 
Solution:  Since - 4.79/- 4.79 is 1 you have 1x,
                          which is writen as just x,
                         on the right hand side of the =.
                    And 8.21/- 4.79 = -1.713987474
                         (round to 2 places after the decimal)
                         so you have -1.71 on the left hand side of the =.
                     x = -1.71
  Check: Substitute -1.71 in for x in the original equation
                         - 4.79 x = 8.21
               - 4.79 (-1.71) = 8.21 and  8.19 = 8.21
                         so -1.71  is the answer to the equation.
                (Remember we had to round our solution to 2 decimal
                places so in the check so there is a slight rounding error.)


bullet3 Practice Exercises

Exercise 1:  5x = 60
 
Exercise 2:  -2.6x = 17.8  
                       (Round answer to 2 places after the decimal.)
 
Exercise 3:  -7x = 49.63
                      (Round answer to 2 places after the decimal.)
 
Exercise 4:  10x = 6
                        (Leave your answer in reduced fractional form.)
 
Hit next to check your answers.


  • Solutions
    Exercise 1:  Divide both sides by 5
                            x = 12
     
    Exercise 2:  Divide both sides by -2.6
                          x = -6.85
     
    Exercise 3:  Divide both sides by  -7
                           x = -7.09
     
    Exercise 4:  Remember all fractions are a division problem,
                            so divide both sides by 10.
                            6 divided by 10 in fractional form is 6/10,
                             this reduces to 3/5.
                           x = 3/5