Answer:

Explanation:
(y - z) ÷ z y = -2 and z = 4/5
Substitute in the given values for y and z into the equation
(y - z) ÷ z
(-2 - 4/5) ÷ 4/5
Subtract inside the parenthesis (-2 - 4/5)
-2.8 ÷ 4/5
Convert 4/5 into a decimal (in this case that can be done by multiplying both the numerator and denominator by 20)
4/5 = (4 * 20) / (5 * 20) = 80 / 100
80 / 100
Divide numerator and denominator by 10
8/10 = 0.8
Substitute into previous equation
-2.8 ÷ 4/5 = -2.8 ÷ 0.8
Divide

Hope this helps :)