Jesse's World Of Equations

 

LINEAR EQUATIONS

Example Problem: 5x-3=9
5x-3 =9
    +3  +3 
5x=12
12/5x
x=12/5		 1. First thing you have to do is isolate the variable, so to do this get rid of the -3. To get rid of the -3 we have to add 3 to both sides.
2. Once we have isolated the variable we can now figure out the answer. It says 5x equals 12 so to find out what one x equals we have to divide 12 by 5x.
3. This gives u the answer to x.

LITERAL EQUATIONS

Example Problem: E= IR for I
E=IR
E/R=I*R/R
E/R=I		 1.We want to solve for I, so essentially we want to Isolate I on one side of the equation.
2.Well since I time R equals E, then lets get ride of the R on that side. So divide by R on both sides. R/R cancels out so it just leaves I on that side.
3. This gives you E/R=I which is the answer.

EQUATION FOR A LINE

Example 1: Slope Intercept Form
m=5, b=-3 write an equation of the line that has the given slope and y-intercept
y=5x+-3

Example 2: Point Slope Form
Write an equation of the line that passes through the given point and has the given slope.
(0.4), m=2
y-4=2(x-1)-------> y-4=2x-2---------> y=2x+2

Example 3: Standard Form
y=2x+2, put this in Standard form.
y=2x+2---------> -2x+y=2----------------> 2x-y=-2

1.First thing is you must realize the formula for a line is y=mx+b
2.In this problem all u have to do is substitute the numbers in.
3. The formular of Point slope form is y-y1= m(x-x1)
4. First lets go ahead and substitute in what we know.
5. Then solve the equation. Distribute the 2 throughout the parentheses. Then lets isolate the y, so lets add 4 to both sides.
6. And BOO YA, you have your equation of the line.
7. Finally there is Standard form
8. To put the equation of the line in Standard form you just need to have both variables on one side.
9. So lets subtract 2x. Then u get -2x+y=2. Only thing is you can't have a negative number at the BEGGINING of Standard form. So lets distribute the negative through the whole problem. And you have your equation of the line in Standard form. One more thing to remember is that the first variable in Standard form cannot be a Fraction either. So had it been 1/2x you would have to multiply everything in the equation by 2/1. 

It must be butter cause your on a roll, because you now know how to do these types of Equations.


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