Question

if y varies inversely with x and y= -18 when x = 6 , find y when x=5

Answer 1

Answer:

y = -108/5

Step-by-step explanation:

An inverse variation is xy = k where k is a constant

xy =k

6*-18 = k

-108 = k

xy = -108

Let x = 5

5y = -108

Divide by 5

y = -108/5

Answer 2

Problem:

• if y varies inversely with x and y.= -18 when x = 6, find y when x = 5?

Answer:

• $\huge \: \boxed{y = - 21.6}$

Formula:

• $\boxed{y = \frac{k}{x} }$

To find k use the given condition:

Given that:

• $y = -18$
• $x = 6$

Lets try!

• $\:y = \frac{k}{x} \: \: ➡ \: \: \boxed{ k \ = yx}$
• $yx = - 18 \times 6 = \boxed{- 108}$

Equation is:

• $\boxed{y = {\frac{ - 108}{ \: x}}}$

When x = 5 then,

• $\huge{y = \frac{ - 108}{ \: 5}}$
• $\huge\boxed{y = - 21.6}$

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