Cracking The SAT Premium

The equation in the previous example would be –5x + y = 3 when written in the standard form. Using the
information above, you can see that

slope   =   –       =   5

y-intercept =       =   3

x-intercept =       =   –   

The answers for the slope and the y-intercept were the same as when the slope-intercept form was used.
Depending on the form of the equation in the question or in the answers, knowing these line equation facts
can help save time on the test.

Let’s look at how this may be tested.

15.The  graph   of  which   of  the following   equations   is  parallel    to  the line    with    equation    y   =   −3x

−   6   ?

A) x    −   3y  =   3

B) x    −    y  =   2

C) x    +    y  =   4

D) x    +    y  =   5

Here’s How to Crack It

The question asks for the equation of a line that has a slope parallel to the slope of the line given in the
problem. In the form y = mx + b, m represents the slope. So, the slope of the equation given in the
problem, y = –3x − 6, is –3. All you need to do now is find which choice also has a slope of –3.

One way to do that would be to rewrite each answer into the y = mx + b form. However, if you notice

that each equation is presented in the Ax + By = C form, you know that the slope in that form is equal to –

. So, check each answer choice: the slope of (A) is – , or ; the slope of (B) is – or 3; the