Equations and Formulas

Question 1

What you need to know for solving quadratic equations.

ex: x2 + 3x +2 =0

Answer 1

put into this form:

x2 + ax + b = 0
(x + c) (x +d) = 0
c*d must always equal b
c+d must always equal a

Question 2

graphing equations, what formula do you use?

Answer 2

y=mx + b
b = y intercept
m = rise/run
*where the two lines cross is your solution

Question 3

How do you solve systems using the addition/subtraction method?

Answer 3

Eliminate one of the variables 
so in 2x + y = 3
    &  3x +2y = 9 
get the two equations into like forms. 
4x + 2y = 6
3x + 2y = 9 	(both 2y)
cross them out, x has to equal -3 in both equations
then solve for y by plugging x into one of the equations

Question 4

How do you solve an equation using the substitution method?

Answer 4

1. With the two equations, solve for y with one equation, then plug the y in to the other equation.
   2x + y = 3
   y = -2x + 3
   now plug that into the other equation.