How do you find the slope and intercept of #y= -2/5x + 20#?

2 Answers
May 17, 2018

#"slope "=-2/5," y-intercept "=20#

Explanation:

#"the equation of a line in "color(blue)"slope-intercept form"# is.

#•color(white)(x)y=mx+b#

#"where m is the slope and b the y-intercept"#

#y=-2/5x+20" is in this form"#

#"with slope "=-2/5" and y-intercept "=20#

May 17, 2018

Slope #= -2/5#

#y#-intercept #= 20#

Explanation:

The given equation is the standard slope-intercept form of a straight line equation,

#y = mx + c#

where

  • #m =# slope #-># tangent of the angle made by the straight line intercepting one of the axes (#x# or #y#)
  • #c =# the #y#-intercept, which remains constant.

Thus putting your equation in accordance with the standard equation, the slope is #-2/5# and the #y#-intercept is #20#.

graph{y = -2/5x + 20 [-80, 80, -40, 40]}

Since the slope is negative in magnitude, the tangent of the angle is greater than #180^@# and hence, the straight line cuts the positive #x# axis. Otherwise, in case of a positive slope, the straight line only cuts the positive #y# axis, thus giving us the intercept.

Here the straight line cuts the positive #y# axis at #(0,20)# and hence the #y#-intercept is #20#.