Question

If a line crosses the y-axis at (0, 1) and has a slope of 45, what is the equation of the line?

A) 4y − 5x = 5

B) y − 4x = 5

C) 5y + 4x = 5

D) 5y − 4x = 5

Answer 1

Equation is y - 1 = 4/5(x - 0) => 5(y - 1) = 4x => 5y - 5 = 4x => 5y - 4x = 5

Answer 2

The general equation of a line is expressed as:

y = mx + b 

where m is the slope and b is the y-intercept.

We are given the slope of the line and its y-intercept (m = 4/5, b = 1).

y = (4/5)x + 1 

5(y - (4/5)x = 1)

5y - 4x = 5

The answer should be option D.