# How do you write an equation in slope intercept form given that the line passes through the points (-1,1) and (2,3)?

##### 1 Answer

May 1, 2018

#### 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)=(-1,1)" and "(x_2,y_2)=(2,3)#

#rArrm=(3-1)/(2-(-1))=2/3#

#rArry=2/3x+blarrcolor(blue)"is the partial equation"#

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

#"the partial equation"#

#"using "(2,3)" then"#

#3=4/3+brArrb=9/3-4/3=5/3#

#rArry=2/3x+5/3larrcolor(red)"in slope-intercept form"#