SAT Math : How to find out if lines are parallel
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Example Questions
Example Question #33 : Coordinate Geometry
Which of the following are parallel to the line 
A.
B.
C.
D.
E.
D & E
A & D
None of the given answers
C & D
A, B, & C
A & D
In order for two lines to be parallel, they must have the same slope and different y-intercepts. In slope-intercept form, the slope of the coefficient of our 
We want to find lines that have a slope of 
Example Question #31 : Lines
Given lines on the coordinate plane as follows:
Line A has equation
Line B has equation
Line C has equation
Which of the following is a true statement?
Line A and Line C are parallel to each other, but Line B is parallel to neither Line A nor Line C.
Line B and Line C are parallel to each other, but Line A is parallel to neither Line B nor Line C.
Line A and Line B are parallel to each other, but Line C is parallel to neither Line A nor Line B.
Line A, Line B, and Line C are parallel to one other.
No two of Line A, Line B, and Line C are parallel to each other.
No two of Line A, Line B, and Line C are parallel to each other.
Two lines are parallel if and only if they have the same slope. Therefore, we must find the slope of each line. We do this by rewriting each equation in slope-intercept form 
In each case, solve for 
Line A:
The slope of Line A is the 
Line B:
The slope of Line Bis the 
Line C:
The slope of Line C is the 
No two of the given lines have the same slope, so no two are parallel.
Example Question #35 : Coordinate Geometry
Given Lines A, B, and C on the coordinate plane as follows:
The equation of Line A is 
The equation of Line B is 
The equation of Line C is 
Which of the following is a true statement?
Line A and Line C are parallel to each other, but Line B is parallel to neither Line A nor Line C.
Line A, Line B, and Line C are parallel to one other.
Line A and Line B are parallel to each other, but Line C is parallel to neither Line A nor Line B.
Line B and Line C are parallel to each other, but Line A is parallel to neither Line B nor Line C.
No two of Line A, Line B, and Line C are parallel to each other.
Line A, Line B, and Line C are parallel to one other.
Two lines are parallel if and only if they have the same slope. Therefore, we must find the slope of each line. We do this by rewriting each equation in slope-intercept form
In each case, solve for
Line A:
This equation is already in slope-intercept form. The slope of Line A is the 
Line B:
The slope of Line B is the 
Line C:
The slope of Line C is the 
In each case, the slope is 
Example Question #36 : Coordinate Geometry
Given Lines A, B, and C on the coordinate plane as follows:
Line A has intercepts 
Line B has intercepts 
Line C has intercepts 
Which statement is true?
Lines A, B, and C are all parallel to one another.
No two of Lines A, B, and C are parallel.
Lines A and B are parallel to each other, but Line C is parallel to neither line.
Lines B and C are parallel to each other, but Line A is parallel to neither line.
Lines A and C are parallel to each other, but Line B is parallel to neither line.
Lines A and C are parallel to each other, but Line B is parallel to neither line.
Two lines are parallel if an only if their slopes are equal. The slope of a line with 
Calculate the slope of Line A by setting 
Calculate the slope of Line B by setting 
Calculate the slope of Line B by setting 
Lines A and C have the same slope and are parallel; Line B has a different slope and is not parallel to the other two.
Example Question #41 : Lines
Which of the following lines is parallel to:
First write the equation in slope intercept form. Add 
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