The root of the equation kx = 4 is 0.8. Find the root of the equation kx = -2.

If the decimal 0.8 is the root of the equation kx = 4, then

k * 0.8 = 4 (in order to find an unknown factor, you need to divide the product by a known factor);

k = 4: 0.8;

K = 40: 8;

k = 5.

Therefore, we solve an equation of the form:

5 * x = -2 (in order to find an unknown factor, you need to divide the product by a known factor);

x = -2: 5;

x = -2/5.

Answer: -2/5.