Basic Math

• Set - a collection or group of objects
• Element - an object belong to the set
• Empty/Null Set - A set containing no elements
• ∪ - A union B
• ∩ - A intersection B
• Complement of a Set - a set that contains the elements present in the universal set but not in set A
• Natural numbers - N ={1,2,3,4,...}
• Integers - Z ={...,-2,-2,0,1,2,...}
• Rational Numbers - Q = {a/b | a,b are integers and b≠0}
• Ratio - the comparison of two quantities of the same unit
• Rate - the comparison of two quantities of different units of measure
• Percent - ratio whose second term is 100
• Cartesian coordinate system - a system where every point in the plane is uniquely identified with a pair of real numbers
• Abscissa - the x-position of a point in the coordinate plane
• Ordinate - the y-position of a point in the coordinate plane
• x-intercept - the abscissa of the point where the line intersects with the x-axis
• y-intercept - the ordinate of the point where the line intersects with the y-axis
• Slope - measures the steepness of the line
• Slope - the quotient of the change in the y-coordinates over the change in x-coordinates
• General Equation of a Line - Ax+By+C=0
• Slope-intercept form - y=mx+b
• Point-slope form - y-y₁=m(x-x₁)
• Intercept form - (x/a)+(y/b)=1
• system of linear equations - a set of linear equations
• Linear Systems: independent system - has exactly one solution pair (x,y)
• Linear systems: inconsistent system - has no solution
• Linear systems: Dependent system - has infinitely many solutions
• Coincident lines - two lines that line up exactly with each other so that all points on the two lines are the same
• Additive Inverse - what you add to a number to get a sum of 0.
• Multiplicative Inverse - what you multiply to a number to get a product of 1.
• 5% = 0.05 = 1/20
• 10% = 0.1 = 1/10
• 20% = 0.2 = 1/5
• 30% = 0.3 = 3/10
• 25% = 0.25 = 1/4
• 40% = 0.4 = 2/5
• 50% = 0.5 = 1/2
• 60% = 0.6 = 3/5
• 70% = 0.7 = 7/10
• 75% = 0.75 = 3/4