The equation of the line thru the points (2, 3) and (7, 4)) is?

Question

a. x - y + 1 = 0

b. x + y - 5 = 0

c. x - y + 5 = 0

d. x - 5y + 13 = 0

or none of these

Answer 1

a) 2-3+1 = -1+1=0; 7-4+1=3+1=4 not 0, its not
b) 2+3-5 = 5-5=0; 7+4-5=11-5=6 not 0, its not
c)2-3+5= -1+5=4 not 0, its not

d) 2-5(3)+13 = 2-15+13=-13+13=0; 7-5(4)+13= 7-20+13=0
yeah, both equal 0, then it is the equation of the line thru the points (2, 3) and (7, 4)

Answer 2

The slope of the line joining the two given points is (4-3)/(7-2)=1/5.
The slope of a line y=mx+b is m. Here as m is 1/5, the only equation that fits the given slope is (d).
Even otherwise, it is easily seen that (d) is the only equation that is satisfied by substituting the two sets of the given coordinates of the two points.

Answer 3

The easiest thing you can do, since this is a multiple choice question, is to plug in the x and y corrdinate from your two points to each of the answers and choose the one that evaluate true for both of the points.

Learning how to do this is more important than being able to just answer the question.

Another (more complex) way to do this is to find a slope using the two points you have, and the Y intercept, then arrive at the formula.

Answer 4

It's (x-2)/(7-2) = (y-3)/(4-3)

Work it out from that.

Answer 5

Lol, are you in the middle of a test? :P
it's x-5y-13=0 , none : (x-x1)/(y-y1)=(x-x2)/(y-y2) or I think that was it :p

Answer 6

Its 'd'. Just substitute n check. its easy..