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Write the equation of a line that passes through the points ( 2 , - 5 ) and ( 8 , - 2 )

1 Answer

5 votes

Answer:


y=(1)/(2)x-6

Explanation:

Hi there!

Linear equations are typically organized in slope-intercept form:
y=mx+b where m is the slope and b is the y-intercept (the value of y when the line crosses the y-axis)

1) Determine the slope (m)


m=(y_2-y_1)/(x_2-x_1) where two points that fall on the line are
(x_1,y_1) and
(x_2,y_2)

Plug in the given points (2,-5) and (8,-2)


m=(y_2-y_1)/(x_2-x_1)\\=(-2-(-5))/(8-2)\\=(-2+5)/(8-2)\\=(3)/(6)\\=(1)/(2)

Therefore, the slope of the line is
(1)/(2). Plug this into
y=mx+b:


y=(1)/(2)x+b

2) Determine the y-intercept (b)


y=(1)/(2)x+b

Plug in one of the given points and solve for b


-5=(1)/(2)(2)+b\\-5=1+b

Subtract 1 from both sides to isolate b


-5-1=1+b-1\\-6=b

Therefore, the y-intercept of the line is -6. Plug this back into
y=(1)/(2)x+b:


y=(1)/(2)x+(-6)\\y=(1)/(2)x-6

I hope this helps!

User Jakub Gawecki
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