We can simplify the given expression by multiplying the terms together:

(7у-3) (48+0.6у) (1.5-у) = 0

Expanding each pair of terms first:

= (7у 48 + 7у 0.6у - 3 48 - 3 0.6у) * (1.5 - у)

= (336y + 4.2y^2 - 144 - 1.8y) * (1.5 - y)

Now distributing the terms:

= 336y(1.5) + 336y(-y) + 4.2y^2(1.5) + 4.2y^2(-y) - 144(1.5) - 144(-y) - 1.8y(1.5) - 1.8y(-y)

= 504y - 336y^2 + 6.3y^2 - 4.2y^3 - 216 + 144y - 2.7y - 1.8y^2

Combining like terms:

= -4.2y^3 + 0.6y^2 + 123.3y - 216

Therefore, the simplified expression is: -4.2y^3 + 0.6y^2 + 123.3y - 216 = 0.