How do you find the general form of the line passing through (-1,2) and (2,5)?

2 Answers
Jun 11, 2017

y=x+3

Explanation:

First, find the slope. To do this, plug in values for this equation.
m=(y2-y1)/(x2-x1)
m is the slope and the values are your original coords.
m=(5-2)/(2--1)
m=3/3
m=1
Now that we have the slope, we use it to find the y-intercept, and the slope-intercept form.
We use point-slope for this.
y-y1=m(x-x1)
y-2=1(x--1)
y-2=(x+1)
y-2=x+1
y=x+3
The slope is 1, and the y-intercept is 3. The slope-intercept form is "y=x+3", and the point-slope form is "y-2=1(x+1)"

Jun 11, 2017

x-y+3=0

Explanation:

"the equation of a line in "color(blue)"general form" is.

color(red)(bar(ul(|color(white)(2/2)color(black)(Ax+By+C=0)color(white)(2/2)|)))
where A is a positive integer and B, C are integers.

"to begin express the equation in "color(blue)"slope-intercept form"

• y=mx+b

"where m represents the slope and b, the y-intercept"

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

color(red)(bar(ul(|color(white)(2/2)color(black)(m=(y_2-y_1)/(x_2-x_1))color(white)(2/2)|)))
where (x_1,y_1),(x_2,y_2)" are 2 coordinate points"

"the points are " (x_1,y_1)=(-1,2),(x_2,y_2)=(2,5)

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

rArry=x+blarr" is the partial equation"

"to find b use either of the 2 given points"

"using " (2,5)" then"

5=2+brArrb=3

rArry=x+3larrcolor(red)" in slope-intercept form"

rArrx-y+3=0larrcolor(red)" in general form"