Given the equation 5x 4y 2 answer the following questions

Given the equation 5x + 4y = 2, answer the following questions. If x decreases by 16 units, what is the corresponding change in y?

the corresponding change in y = 20

Given 5x + 4y = 2

4y = 2 - 5x

y = -(5/4)x + 2/4 (here y = f(x))

f(x) = -(5/4)x + 2/4

Insert x-16 in above equation
f(x-16) = (-5/4)*(x-16)+2/4 ------>(here-5/4.(-16) = +80/4)

f(x-16) = (-5/4)*x+80/4 + 2/4) = (-5/4)*x + 82/4

f(x)-f(x-8)=((-5/4)*x+2/4) - ((-5/4)*x+82/4)

= -5/4*x + 2/4 + 5/4*x - 82/4 (here +5/4*x and -5/4*x gets cancel)

=2/4-82/4=-80/4=-20