Get this in slope-intercept form by adding 5y to each side:
4x - 5y + 5y = 5y + 20
Cancel the 5y's on the left side and we get:
5y + 20 = 4x
Subtract 20 from each side
5y + 20 - 20 = 4x - 20
Cancel the 20's on the left side and we get:
5y = 4x - 20
Divide each side by 5:
5y/5 = 4x/5 - 4
y = 4x/5 - 4
So we have a slope of 4/5
to find our y-intercept, we set x = 0:
y = 4(0)/5 - 4
y = 0 - 4
y = -4
If we want a line perpendicular to the line above, our slope will be the negative reciprocal:
The reciprocal of 4/5 is found by flipping the fraction making the numerator the denominator and the denominator the numerator:
m = 5/4
Next, we multiply this by -1:
-5/4
So our slope-intercept of the perpendicular line with the same y-intercept is:
y = -5x/4 - 4
ncG1vJloZrCvp2O6osDHnJylnZKntrXFjZympmeTpLquwc2iq7JnpJ2%2Fpq3DrGaesKChrqq6jK2fnmWjqbKxv4yypq5lp6TCrbCMrZiknV2pvG6yyKebZpmeYrKywcCtoKimXZu8s3nToZxmpJmjsm68xKunnqaUnrC2uMCrZK2nXWnFboHYZmlpZZGjsW9%2Blm9uaA%3D%3D