caranya gimana ya??tolong dijelaskan

caranya cari dulu masing masing akar
[tex] \sqrt{784 } = 28[/tex]
[tex] \sqrt{49} = 7[/tex]
[tex] \sqrt{289} = 17[/tex]

lalu

z
[tex]28 + 7 + - 17 = 18[/tex]

 [tex] \sqrt{784} [/tex]= 28
 [tex] \sqrt{49} [/tex] = 7
 [tex] \sqrt{289} [/tex] = 17
28 + 7 - 17 = 18 (A)