MATH - SCIENCE INTEGRATION

bullet1 SOLVING ONE STEP EQUATIONS

bullet2 Addition

  x + a = b
Add the inverse (opposite) of a to both sides of the equation.


bullet3 Example 1

x + 6 = 22
 
Solve:  Add -6 to both sides of the equation  x + 6 + (-6) = 22 + (-6)
 
Solution:   6 + (-6) = 0
                           so just x remains on the right hand side of the =
                    22 + (-6) = 18 so 18 is on the left hand side of the =
                     x = 18
 
Check:  Substitute 18 in for x in the original equation.  x + 6 = 22
                18 + 6 = 22 and 22 = 22 so 18  is the correct answer.


bullet3 Example 2

x + (-12.46) = -42.8
 
 Solve:  Add 12.46 to both sides of the equation  
                  x + (-12.46) +12.46 = -42.8 + 12.46
 
Solution:   -12.46 + 12.46 = 0
                          so just x remains on the right hand side of the =
                   -42.8 + 12.46 = -30.34
                           so -30.34 is on the left hand side of the =
                     x = -30.34
 
 Check:  Substitute -30.34 in for x in the original equation.                    
                       x + (-12.46) = -42.8     
               -30.34 + (-12.46) = -42.8 and -42.8 = -42.8
                       so -30.34  is the correct answer.


bullet3 Example 3

x + 3/4 = 7/12
 
Solve:  Add -3/4 to both sides of the equation  
                 x + 3/4 + (-3/4) = 7/12 + (-3/4)
 
Solution:  3/4 + (-3/4) = 0
                        so just x remains on the right hand side of the =
                    7/12 + (-3/4) = -1/6
                         so -1/6 is on the left hand side of the =
                    x = -1/6
 
Check:  Substitute -1/6 in for x in the original equation.  
                     x + 3/4 = 7/12
                -1/6 + 3/4 = 7/12 and 7/12 = 7/12
                       so -1/6  is the correct answer.


bullet3 Practice Exercises

Exercise 1:  x + 17 = 53
 
Exercise 2:  x + (-3.67) = 58.25
 
Exercise 3:  x + 2/5 = 17/20
 
Exercise 4:  1.9 + x = - 4.2
 
Exercise 5:  -272 + x = -130
 
Hit next to check your answers.


  • Solutions
    Exercise 1: Add -17 to both sides
                           x = 36
     
    Exercise 2:  Add 3.67 to both sides
                            x = 61.92
     
    Exercise 3:  Add - 2/5 to both sides
                            x = 9/20
     
    Exercise 4:  Add -1.9 to both sides
                           x = 6.1
     
    Exercise 5:  Add 272 to both sides
                           x = 142