How do you write the equation of the line in slope intercept form passing through (1, 2) and (2, 5)?

3 Answers
Apr 20, 2018

Answer:

y = 3x -1

Explanation:

  1. Find the slope by using the formula #(y_2-y_1)/(x_2-x_1)#
    You wil get: #(5-2)/(2-1)#
    Simplify to get 3

  2. Find the y-intercept by plugging in one kf the pairs and the slope into the y = mx + b equation. It doesn’t matter which pair you use.

You see 2 = 3(1) + b
Solve for b
2 = 3 + b
-1 = b

  1. Answer is y = 3x -1
Apr 20, 2018

Answer:

#y=3x-1#

Explanation:

the gradient/slope is the difference in the #y# values divided by the difference in the #x# values.

#=># #[5-2]/[2-1]# =#3/1# =3

so the equation of the line is #y=3x+c#

Use (1,2) #=># #2=3xx1+c#
#=># #2=3+c# so #c#=-1

this gives #y=3x-1#

Apr 20, 2018

Answer:

#y=3x-1#

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)=(1,2)" and "(x_2,y_2)=(2,5)#

#rArrm=(5-2)/(2-1)=3#

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

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

#"using "(1,2)" then"#

#2=3+brArrb=2-3=-1#

#rArry=3x-1larrcolor(red)"equation in slope-intercept form"#