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1 vote
What is the equation of the line that passes through the point

(
7
,
2
)
(7,2) and has a slope of
1
1?

User Bky
by
3.9k points

1 Answer

9 votes

Answer:

(y+2)= -3(x-7)

Explanation:

We can use the slope-intercept formula to write this equation. The slope-intercept form of a linear equation is:

y = m x + b

Where m is the slope and b is the y-intercept value.

We can substitute the slope into the formula giving:

y = − 3 x + b

Next, we can substitute the values from the points in the problem for x and y and solve for b :

− 2 = ( − 3x 7 ) + b

− 2 = − 21 + b

21 − 2 = 21 − 21 + b

19 = 0 + b

19 = b

We can now substitute the slope from the problem and the value for b we calculated into the formula to write the equation.

y = − 3 x + 19

Another process is to use the point-slope formula. The point-slope formula states:

( y − y 1 ) = m ( x − x 1 )

Where m is the slope and ( x 1 , y1 ) is a point the line passes through.

Substituting the slope and values from the points in the problem gives:

(y − − 2 ) = − 3 (x-7)

( y + 2 ) = − 3 ( x − 7 )

User Gwik
by
4.3k points