Mathematical Operations and Equations, Study notes of Mathematics

The basics of mathematical operations such as addition, subtraction, multiplication, and division. It also covers the basics of equations and proportions. examples and step-by-step solutions to problems related to these topics.

Typology: Study notes

2019/2020

Available from 02/28/2023

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* multiply
/ divide
+ add/positive
- subtract/negative
(,) calculate what’s inside first
Expressions:
Combinations of mathematical symbols and operators
Example:
5 + 3
Symbols: 5 and 3
Operator: +
X - 12
Variable: X
Symbol: 12
Operator: -
5t
X
Variable: t and x
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  • multiply / divide
  • add/positive
  • subtract/negative (,) calculate what’s inside first Expressions: Combinations of mathematical symbols and operators Example: 5 + 3 Symbols: 5 and 3 Operator: + X - 12 Variable: X Symbol: 12 Operator: - 5t X Variable: t and x

Basics of equations X + 23 = 45 Variable: X Constants: 23 and 45 =: equal sign/ fulcrum Because an equation represents a scale, it can also be manipulated Initial equation/problem X + 23 = 45 Subtract 23 from each side X + 23 - 23 = 45 - 23 result/ answer X = 22 Initial equation/ problem X + 23 = 2x + 45 Subtract X from each side X - X + 23 = 2x - x + 45 Result 23 = X + 45 Subtract 45 from each side 23 - 45 = X + 45 - 45 Result -22 = x Answer X = -

Using Division Recall: “ x + 23 = 3x + 45 “ applying addition and subtraction gave: 2x = - Divide by the coefficient of the variable since the coefficient of x is 2, we divide each side of the equation by 2 : After dividing by 2 1x = - Finally rewritten as x - Associative Property Associative property of addition Exp. 1: (14 + 6) + 7 = 14 + (6 + 7) 20 + 7 = 14 + 13 27 = 27 Exp. 2: (52 + 7) + 13 = 52 + (7 + 13) 69 + 13 = 52 + 19 72 = 72

Associative property of multiplication Exp. 3: (3 * 5) * 6 = 3 * (5 * 6) 15 * 6 = 3 * 30 90 = 90 Exp. 4: 2 * (18 * 10) = (2 * 18) * 10 2 * 180 = 36 * 10 360 = 366 Proportions Proportion Basics Compares two ratios to make an equivalent fractions 1 apple : 3 oranges For every apple, there are 3 oranges Exp. Apple orange 2 : 3

divide by 9 50 = x 50 =? 25/x = x/ X * X = 25 * 1 X squared = 5

  1. Find a number squared that is equal to 25
  2. Change problem to x = square root of 25 X squared = 5 x/12 = 3 x/12 = 3/1 12 * 3 = x * 1 36 = x X = 36 Word Problems 15 apples and 12 oranges – How many pieces of fruit do you have? 27 15 + 12 = x There are 27 pieces of fruit Two consecutive numbers have a sum of 91. What are the numbers?
  • X + (x + 1) =
  • Initial equation X + (x + 1)
  • After combining like terms 2x +
  • Subtract 1 from each side 2 x
  • Divide each side by 2 x