Question

What is the equation of the following line? Be sure to scroll down first to see all answer options.

A. Y= 7x
B. Y= 21x
C. Y= -7x
D. Y= -3x
E. Y= 1/5x
F. Y= 3x

Answer 1

Since our line passes through the y-axis at (0,0) the equation will not contain a y-intercept for it being equal to 0. We see that it goes from (0,0) to (1,7) which means it runs 1 and rises 7.... 7/1 so it has a slope of 7.

The equation is...
y = 7x

Answer 2

The equation of a line is y = 7x .

Option (A) is correct .

Explanation:

As the equation of the line in the form

y = mx + c

Where m is the slope and c is the y - intercept.

`m = (y_(2) - y_(1))/(x_(2) - x_(1))`

Thus

As shown in the figure the line pass through the point (0,0) and (1,7) .

Thus

`m = (7 - 0)/(1 - 0)`

m = 7

As the line passes through the origin, the y intercept is already determined (it is 0 since the line will pass through the y axis at 0).

Thus

c = 0

Put the value of m and c in the equation

y = 7x + 0

y = 7x

Therefore the equation of a line is y = 7x .

Option (A) is correct .