obs23
In the xy coordinate plane, does the point (3,4) lie on line t?
(1) The line 5y-45=-x is perpendicular to the line t.
(2) The line with the equation \(y= \frac{3}{4}x - 11\) intersects the line t when y=-11.
Please show a step by step approach here and explain why it is not
. I do not understand the official explanation.
Keep in mind, there are two ways in which you can define a line t:
- You are given two distinct points that lie on that line. You join the two points and you have a defined line.
- You are given one point and the slope of the line. You make a line with the given slope on the point.
Question: In the xy coordinate plane, does the point (3,4) lie on line t?
You need to define line t to figure out if a point lies on it.
(1) The line 5y-45=-x is perpendicular to the line t.
This gives you the slope of line t but you don't have any point on it. So you cannot define line t.
Not sufficient.
(2) The line with the equation \(y= \frac{3}{4}x - 11\) intersects the line t when y=-11.
When y = -11, you can find the value of co-ordinate x by plugging in \(y= \frac{3}{4}x - 11\).
So you will have a point which lies on line t. But you don't have another point.
Hence you cannot define line t using this statement alone.
Using both stmnts, you get the slope of line t and a point that lies on it. This will help you define t uniquely. So you will be able to find out whether (3, 4) lies on it.
Sufficient.
Answer (C)