Mathematics

Question

how do I solve this equation

1 Answer


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    REVIEW OF BASIC MATHEMATICAL RULES
     
       Rules for Signed Numbers     Addition Rules:   positive + positive =  (add) positive  Ex:  2 + 1 =  3
      negative + negative =  (add) negative  Ex:  –3+ (–5) = –8
      negative + positive =  (subtract) and   Ex:  2 + (–10)  = –8      take sign of number with largest   Ex:  –14 + 16 =  2      absolute value
     
    -------------------------------------------------------------------------------------------------------------------   Remember:  –(–7) means take the opposite of (–7)  =  7  ----------------------------------------------------------------------------------------------------------------- Subtraction Rules:  Change all “subtraction” to addition and take the opposite sign of the following number then follow the addition rules.
     
      Ex:   –7 – (9)  means    Ex:  –3 – (–10)  means            –7 + (–9)  =  -16           –3 + (10)  =  7
     
      Ex:   –8 + (–9) – (–1) – 2       -change all subtraction signs as indicated above
              –8 + (–9) + (1) + (–2)     -do addition and subtraction from left to right
       –17    +   (1) + (–2)
              –16        +  (–2)  = –18
     
     Multiplication/Division Rules:  The rules for multiplication and division are the same.    positive  ( or )  positive  =  positive Ex:  10  2 = 5   negative  ( or )  negative  =  positive Ex:  –4  (–3) = 12   negative  ( or )  positive  =  negative Ex:  18 (–2)  –9   
    Tutoring and Testing Center 
     Order of Operations:   Parenthesis; Exponents; Multiplication or Division from left to right;   Addition or Subtraction from left to right
     
      P.E.M.D.A.S.
     
     
      Ex:       -7 + 20 ÷ (-4)(5)- 32 - (-8) + 4(3 – 7)           1. Parenthesis    -7 + 20 ÷ (-4)(5) - 32- (-8) + 4(-4)  2. Exponents    -7 + 20 ÷ (-4)(5) - 9  - (-8) + 4   3. Division    -7 +     (-5)    (5) - 9  - (-8) + 4  4. Multiplication    -7 +        (-25)     - 9  - (-8) + 4  5. Addition              -32            - 9  - (-8) + 4  6. Change subtraction signs              -32      +   (-9)  + (8) + 4                       -41          +   8  + 4                       -33        + 4  = -29
     
    ---------------------------------------------------------------------------------------------------------------------      Percent Equation: 
     
      What percent of  the total is the part?       %            T       =     P
     
     
    12% of the 200 students enrolled in freshman English earned a grade of “A” in the class.  How many students earned an “A”?                                               Ex:  12%  of  200  is  what         - Translate into an equation             (“of” means “multiply”; “is” means “equal”)    0.12   x   20   =   x  - Change % to a decimal                                           24  =  x
     
     
     
     
     
     Percent Decrease/Increase:    Last year student employment jobs paid $7.25 per hour.  This year student employment jobs are paying $8.45 per hour.  What percent increase was given to student employment jobs?
     
          1. Find the amount of the increase:  $8.45 - $7.25 = $1.20
     
          2. Which (hourly pay) total received an increase?  The $7.25 per hour got increased.
     
          3. What % of the total was the increase?      x  7.25 = 1.20        7.25x    = 1.20
          
    25.7 20.1
    25.7 25.7  x      x  = .1655      x  = 16.6% increase --------------------------------------------------------------------------------------------------------------------    Place Value:     101 = 10  10–1 = 0.1   102 = 100  10–2 = 0.01   103 = 1000  10–3 = 0.001   104  =  10000  10–4 = 0.0001 ------------------------------------------------------------------------------------------------------------------- 
     
    Angles:    Acute Angles:  less than 90 degrees Obtuse Angles:   more than 90 degrees Right Angles:   90 degrees Straight Angle:   180 degrees    Complementary Angles:   Two angles the sum of whose measures is 90 degrees  Supplementary Angles:   Two angles the sum of whose measures is 180 degrees   
     
     
     
     
     
     
    Triangles:   Triangles:    Sum of the interior angles is 180 degrees  Isosceles Triangle:   Two equal sides; two equal angles  Equilateral Triangle:  Three equal sides;  three equal angles
     
    Right Triangles - Pythagorean Theorem:  a2 + b2 = c2, where a and b are the measures of the legs of the triangle and c is the hypotenuse.
     
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    Statistics:  
     Mean (average) =  sum of all values divided by number of values Median =   middle value when the values are arranged numerically Mode =   the data value that occurs most frequently  --------------------------------------------------------------------------------------------------------------------    Probability: P(A) =   sizesampletotal Aoffrequencythe
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