unit 1-2 test Flashcards
describe an identity
when the equation equals each other, so any number can work
3x+6 = 3x+6
All real numbers
describe a conditional
only has a set number of answers
2x = 10 x = 5
1 solution
describe a contradiction
a equation is deemed false
-5x+7 = -5x+3 7 = 3
No solution
explain the meaning of < > signs
> :greater than, O, ()
< :less than, O, ()
explain the meaning of <> or equal to signs
> _ : greater than(or equal to), @, []
<_ : less than (or equal to), @, []
what are the rules of solving inequalities
-always use () on infinities cause they’re never ending
-if dividing with a negative, make sure to flip the inequality sign
- < = <—
- > = —> except when there is 2 inequalities
what is standard form of an equation
Ax + by = c
- A is always positive
- No fractions
what are rules to remember for 2.1/ graphing
- if given a point and told to find the solution of an equation, just plug the point in.
- if it asks to solve y for a standard form equation, turn it into slope-intercept form
- if there’s only x, cross our y in middle of table and vice versa.
things to remember for 2.2/ slope
-slope equation: y2-y1 over x2-x1
-to find slope from standard equation: m = -A over b
things to remember for 2.2/ slope
-slope equation: y2-y1 over x2-x1
-to find slope from standard equation: m = -A over b
things to remember on lines of slope
-parallel lines: same slope
-perpendicular lines: negative reciprocal of slope
-slope = 0, line is horizontal <—>
- slope is undefined, line is vertical ^v
things to remember for 2.3/ writing linear equations
- to find slope from 2 points: m= triangles y over x (triangle subtraction)
- then find b with point slope: y-y1 = m(x-x1)
- or with slope-intercept = y = mx+b
more on 2.3, 0 and undefined
-if slope is 0, put y = y coordinate
-if slope is undefined, put x = x coordinate
what are the rules to remember in 2.4
solid line = equal to
dotted line = <>
< = below
> = above
vertical line > = right shaded
