What is the equation of a line that passes through (1,3) and (4,9)

y = 2x + 1 is the equation of a line that passes through (1,3) and (4,9)

Solution:

Given that we have to write the equation of a line that passes through (1,3) and (4,9)

Let us first find the slope of line

The slope of line is given as:

Here the given points are (1,3) and (4,9)

Substituting the values in formula, we get,

Thus slope of line is 2

The equation of line in slope intercept form is given as:

y = mx + c -------- eqn 1

Where, "m" is the slope and "c" is the y - intercept

To find the y intercept, substitute (x, y) = (1, 3) and m = 2 in eqn 1

3 = 2(1) + c

c = 1

Thus the equation of line is:

Substitute c = 1 and m = 2 in eqn 1

y = 2x + 1

Thus equation of line is found

the answer is y < -3 or   y > 3

-3y > 7 + 2

-3 y > 9

y < -3