# What's the equation of a line that passes through (-4,1) and (0,5).?

##### 2 Answers

#### Explanation:

#"the equation of a line in "color(blue)"slope-intercept form"# is.

#•color(white)(x)y=mx+b#

#"where m is the slope and b the y-intercept"#

#"to calculate m use the "color(blue)"gradient formula"#

#•color(white)(x)m=(y_2-y_1)/(x_2-x_1)#

#"let "(x_1,y_1)=(-4,1)" and "(x_2,y_2)=(0,5)#

#rArrm=(5-1)/(0-(-4))=4/4=1#

#rArry=x+blarrcolor(blue)"is the partial equation"#

#"to find b substitute either of the 2 points into the"#

#"partial equation"#

#"using "(0,5)" then"#

#5=0+brArrb=5#

#rArry=x+5larrcolor(red)"equation in slope-intercept form"#

#### Explanation:

The formula to get the equation of a straight line knowing two points that lie on it is:

where the two points are

And by substituting you get:

And by simplifying you get:

so the equation is