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Learn how to solve linear equations for Y in order to graph them accurately following a step-by-step guide. Understand how to manipulate equations and graph the linear functions effectively.
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Graphing linear equations By Robert O. Mills Jr. Hermitage High School Henrico County Public Schools
Part One Solving for Y
In order to graph a linear equation you must first solve for y.
Given the Problem : x+y=4
First check to see if y is + or –. x+y=4 If y is + you leave it alone.
What number or factor is on the same side of the equation as + y? x+y=4
Move that number or factor to the other side of the = and change its sign. x+y=4
Move that number or factor to the other side of the = and change its sign. y=4-x
Your answer is: y=4-x
Given the Problem : x-y=4
First check to see if y is + or –. x-y=4 If y is - you move y to the other side of the = and change it to +y.
What number or factor is on the same side of the equation as + y? x=4+y
Move that number or factor to the other side of the = and change its sign.
x-4=y Your answer is:
x-4 =y or y=x-4
Given the Problem : x+2y=4
First check to see if y is + or –. x+2y=4 If y is + you leave it alone.
What number or factor is on the same side of the equation as + y? x+2y=4
Move that number or factor to the other side of the = and change its sign. x+2y=4
Move that number or factor to the other side of the = and change its sign. 2y=4-x
If the +y factor has a co-efficient it must lose it. The factors and numbers on the opposite side of the = become a fraction with the y co-efficient as the denominator. 2y=4-x
If the +y factor has a co-efficient it must lose it. The factors and numbers on the opposite side of the = become a fraction with the y co-efficient as the denominator.
Given the Problem : 2x-2y=4
First check to see if y is + or –. 2x-2y=4 If y is - you move y to the other side of the = and change it to +y.
What number or factor is on the same side of the equation as + y? 2x=4+2y
Move that number or factor to the other side of the = and change its sign.
2x-4=2y Your answer is:
2x-4 =2y or 2y=2x-4
If the +y factor has a co-efficient it must lose it. The factors and numbers on the opposite side of the = become a fraction with the y co-efficient as the denominator. 2y=2x-4
If the +y factor has a co-efficient it must lose it. The factors and numbers on the opposite side of the = become a fraction with the y co-efficient as the denominator.
Advanced Level • There are times when it will be necessary to work the equation to a simpler level. • For example the formula for slope intercept is y = mx + b. Any denominator in this case must be eliminated. How to do this?
Most often when we think of the distributive property, we are thinking of using it with ( ) and the operation is multiplication. In the previous example the line is also a grouping tool with the operation division.