No.150 Finding an Equation from a Point
POINT
Substitute the given point into \(y=ax+b\). If the slope is known, substitute \(a\); if the y-intercept is known, substitute \(b\).
Example
1
Find the equation of the line through \( (2,7) \) with slope \(3\).
\(y=3x+1\)
2
Find the equation of the line through \( (4,-1) \) with y-intercept \(3\).
\(y=-x+3\)
TRY
TRY 1
Through \( (3,8) \), slope \(2\).
\(y=2x+2\)
TRY 2
Through \( (-2,5) \), slope \(-3\).
\(y=-3x-1\)
TRY 3
Through \( (2,5) \), y-intercept \(1\).
\(y=2x+1\)
TRY 4
Through \( (-3,4) \), y-intercept \(-2\).
\(y=-2x-2\)