I need help with finding an equation to a line.

Question

Its finding an equation with the intercepts x=-1 and y=3.
Ive gotten the slope of -3 but i don't know where to go from there......

Answer 1

The x-intercept are where the graph crosses the x-axis, and the y-intercept are where the graph crosses the y-axis.

an x-intercept is a point in the equation where the y-value is zero,

and

a y-intercept is a point in the equation where the x-value is zero.

x-intercept:

x = -1 and y = 0

y-intercept:

x = 0 y = 3

Two-point form of the linear equation:

y - y1 = [( y2 - y1 ) / ( x2 - x1 ) ] * ( x - x1 )

where (x1,y1) and (x2,y2) are two points on the line with x2 �‚ x1.

In this case:

x1 = - 1

y1 = 0

x2 =0

y2 = 3

So:

y - y1 = [( y2 - y1 ) / ( x2 - x1 ) ] * ( x - x1 )

y - 0 = [( 3 - 0 ) / ( 0 - ( -1 ) ] * ( x - ( - 1 )

y = ( 3 / 1 ) * ( x + 1)

y = 3 * ( x + 1 )

y = 3x + 3

Answer 2

x+2y+z=1
-x+y+2=6
4x-y+3z=-1