What is equation of the line in standard form that passes through (2, 7) and ( -4, 1)?

2 Answers
Dec 13, 2017

y = mx + by=mx+b

y = x+5y=x+5

x-y=-5xy=5

Explanation:

First, find the slope of the equation using

m = (y_2 - y_1)/(x_2 - x_1)m=y2y1x2x1

m = (1-7)/(-4-2)m=1742

m = 1m=1

Second, plug in m (the slope) into the equation y = mx +by=mx+b

So it becomes y = 1x + by=1x+b

Plug in one of the points into the x and yxandy values into the equation above and solve for b.b.

So, (7) = 1(2) + b(7)=1(2)+b

b = 5b=5

Finally, plug in the bb value into the equation to get the standard form equation.

y = x+5" "larry=x+5 re-arrange

x-y=-5xy=5

Dec 13, 2017

x-y=-5xy=5

Explanation:

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

color(red)(bar(ul(|color(white)(2/2)color(black)(Ax+By=C)color(white)(2/2)|)))

"where A is a positive integer and B, C are integers"

"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(red)(bar(ul(|color(white)(2/2)color(black)(m=(y_2-y_1)/(x_2-x_1))color(white)(2/2)|)))

"let "(x_1,y_1)=(2,7)" and "(x_2,y_2)=(-4,1)

rArrm=(1-7)/(-4-2)=(-6)/(-6)=1

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

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

"using "(2,7)" then"

7=2+brArrb=7-2=5

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

rArrx-y=-5larrcolor(red)"in standard form"