Question

Write the equation of the line that has an undefined slope and passes through the point (4, 7).

y = 4
x = 4
y = 7
x = 7

Answer 1

if the line passes through (4, 7) its equation is: x = 4

Answer 2

x=4

Explanation:

For any two points of a line, say
`(x_1,y_1),(x_2,y_2)` the slope of the line is
`m=(y_2-y_1)/(x_2-x_1)`. If the slope is undefined, it is because division by zero, then
`x_2-x_1=0`, that is,
`x_1=x_2`. This means that all the points of the line have the same x-coordinate. Because (4,7) is on the line and its x coordinate is 4, the points (x,y) of the line satisfy the equation x=4.