1. A line has a slope of $-\frac{3}{7},$ and its $y$-intercept is $(0,18)$. What is its $x$-intercept?
2. Find y if the point (-6,y) is on the line that passes through (-1,7) and (3,-2) .
+128408 1) We have the equation
y = (-3/7)x + 18
To find the x intercept, let y = 0
0 = (-3/7)x + 18
-18 = (-3/7)x
-18 (-7/3) = x
42 = x = the x intercept
2) Slope of the line = (-2 - 7) / (3 - - 1) = -9 / 4
Equation of this line is
y = (-9/4) ( x - -1) + 7
y = (-9/4) ( x + 1) + 7
y = -(9/4)x - 9/4 + 28/4
y = -(9/4)x + 19/4
When x = - 6
y = -(9/4)(-6) + 19/4
y = 54/4 + 19/4
y = 73/4
