The square of X varies inversely as the square root of Y and directly as the variable M. When M = 27 and Y = 16, then X = 9. Find the exact value of Y when M = 7 and X = 2

Respuesta :

Answer:

[tex]Y = 441[/tex]

Step-by-step explanation:

Given

M = 27 when Y = 16 and X = 9

Required

Find Y when M = 7 and X = 2

We start by getting the algebraic representation of the given statement

[tex]X^2 \alpha \frac{1}{\sqrt Y} \alpha M[/tex]

Convert the variation to an equation; we have

[tex]X^2 = \frac{KM}{\sqrt Y}[/tex]

Where K is the constant of variation;

When M = 27; Y = 16; X = 9, the expression becomes

[tex]9^2 = \frac{K * 27}{\sqrt{16}}[/tex]

This gives

[tex]81 = \frac{k * 27}{4}[/tex]

Make K the subject of formula

[tex]K = \frac{81* 4}{27}[/tex]

[tex]K = \frac{324}{27}[/tex]

[tex]K = 12[/tex]

Solving for Y when M = 7 and X = 2

Recall that [tex]X^2 = \frac{KM}{\sqrt Y}[/tex]

Substitute values for K, M and X

[tex]2^2 = \frac{12 * 7}{\sqrt{Y}}[/tex]

[tex]4 = \frac{84}{\sqrt{Y}}[/tex]

Take square of both sides

[tex]4^2 = (\frac{84}{\sqrt{Y}})^2[/tex]

[tex]16 = \frac{7056}{Y}[/tex]

Make  Y the subject of formula

[tex]Y = \frac{7056}{16}[/tex]

[tex]Y = 441[/tex]