Respuesta :

Answer:

20

Step-by-step explanation:

we see here that angle RPN is 180 degrees. SPM is 90 degrees so

angle RPS + angle SPM + angle MPN = 180 degrees

(4y - 10) + 90 + y = 180

(4y - 10) + y = 90

5y - 10 = 90

5y = 100

y = 20