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What is vaule of y when x=4'5

1 Answer

4 votes

Answer:


y = 2.096 or
y = (2\sqrt5+6)/(5)}

Explanation:

Given


y = (4)/(x) + \sqrt x + 0.2 - 5x


x = (4)/(5)

Required

Find y


y = (4)/(x) + \sqrt x + 0.2 - 5x

Substitute
x = (4)/(5)


y = (4)/(4/5) + √(4/5) + 0.2 - 5 * 4/5


y = 5 + √(4/5) + 0.2 - 4

Collect like terms


y = √(4/5) + 5 + 0.2 - 4


y = \sqrt{(4)/(5)} + 1.2

Split the surd


y = (\sqrt4)/(\sqrt5)} + 1.2


y = (2)/(\sqrt5)} + 1.2

Rationalize


y = (2\sqrt5)/(\sqrt5*\sqrt5)} + 1.2


y = (2\sqrt5)/(5)} + 1.2

Take LCM and add


y = (2\sqrt5+1.2*5)/(5)}


y = (2\sqrt5+6)/(5)}

or solve as:


y = (2*2.24+6)/(5)}


y = (10.48)/(5)


y = 2.096

User Soccertrash
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