Respuesta :

y = - 4

collect terms in x

xy + 4x = 1 - 20 = - 19 ( factor out x )

x(y + 4 ) = - 19 ( divide both sides by ( y + 4) )

x = [tex]\frac{-19}{y + 4}[/tex]

x will be undefined if the denominator of the fraction is zero

y + 4 = 0 ⇒ y = - 4

x has no solution for y = - 4



MindTrickery

Answer:

y = -4

Step-by-step explanation:

If we look at xy + 5y, we see that both terms share a factor of y. This gives us

                                                   y(x + 5) + 4x + 20 = 1

Similarly, 4x and 20 share a factor of 4, giving us

                                                   y(x + 5) + 4(x + 5) = 1

Now we see that these two terms share a factor of x + 5, so factoring gives us

                                                   (y + 4)(x + 5) = 1

Dividing both sides by y+4 gives us

                                                    x + 5 = 1/(y + 4)

Finally, we subtract both sides by 5 to get

                                                    x = 1/(y + 4) - 5

Thus, since we can not have a 0 in the denominator, we see that if y = -4 then x will have no solution. For any other value of y, we can find the solution for x using this equation.

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