How do you write a line with slope = 3; (1, 5) ?

1 Answer
Apr 21, 2017

See the entire solution process below:

Explanation:

We can use the point-slope formula to write an equation with the slope in the problem and going through the point in the problem. The point-slope formula states: #(y - color(red)(y_1)) = color(blue)(m)(x - color(red)(x_1))#

Where #color(blue)(m)# is the slope and #color(red)(((x_1, y_1)))# is a point the line passes through.

Substituting the slope and values from the point in the problem gives:

#(y - color(red)(5)) = color(blue)(3)(x - color(red)(1))#

We can also find the equation in slope-intercept form. The slope-intercept form of a linear equation is: #y = color(red)(m)x + color(blue)(b)#

Where #color(red)(m)# is the slope and #color(blue)(b)# is the y-intercept value.

Substituting the slope and the value from the point in the problem and solving for #b# gives:

#5 = (color(red)(3) * 1) + color(blue)(b)#

#5 = 3 + color(blue)(b)#

#-color(red)(3) + 5 = -color(red)(3) + 3 + color(blue)(b)#

#2 = 0 + color(blue)(b)#

#2 = color(blue)(b)#

Substituting this #2# for #b# and the slope from the problem into the formula gives the equation for the line as:

#y = color(red)(3)x + color(blue)(2)#