4= √([2d)/9.8] my teacher never taught us this please help

78.4

Step-by-step explanation:

4= √([2d)/9.8]

you square both sides to eliminate the square root so you get

4^2=√([2d)/9.8] ^2

16=2d/9.8

then you multiply both sides by 9.8 and you get

156.8=2d

then you divide both sides by 2 to leave d by itself and get

d=78.4

225x²+4=0

225x²=0-4

225x²=-4

x²=-4/225

x=±√-4/225

whatare you sayig

step-by-step explanation: