Respuesta :

Answer:

15.5 because you have to take away some point

Step-by-step explanation:

you can do 15.8 +5.3 and that would make 21 - 15 and makes 6 so you can round 15.8 to 16 and then you subtract to make 10 then you add 5

>> Answer

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[tex] \: [/tex]

x² = (15.8)² - (5.3)²

x² = 249.64 - 28.09

x² = 221.55

x = √221.55

x ≈ 15