The turner had to grind 180 parts per shift. Having turned 3 more parts per hour, the turner had to make 15 parts

The turner had to grind 180 parts per shift. Having turned 3 more parts per hour, the turner had to make 15 parts 1 hour before the end of the shift. How many parts per hour did the turner turn?

Let the turner have to grind x parts per hour, then:
x + 3 (details) – he grinded in an hour;
180 / x (hours) – a turner planned to work;
(180 – 15) / (x + 3) (hours) – it took the turner to complete the task, except for the remaining 15 parts.
Knowing that at the same time 1 hour remained until the end of the shift, we make the equation:
180 / x – (180 – 15) / (x + 3) = 1;
x ^ 2 – 12 ∙ x – 540 = 0;
x = 30;
30 + 3 = 33 (parts) – the turner sharpened in an hour.
Answer: 33 parts per hour were sharpened by a turner.