Get expert advice and community support for your questions on IDNLearn.com. Join our Q&A platform to receive prompt and accurate responses from knowledgeable professionals in various fields.

Which of the following equations is an example of direct variation?

y + 10 = 2(x + 5)
y = 2(x + 5)
y + 5 = 2(x + 5)
y = x + 5

Please help!


Sagot :

Direct variation is when  x/y = constans 
That's mean, that   formula of direct variation is y=kx   (k inequal 0)

First:
y+10=2(x+5)
y+10 = 2*x + 2*5
y+10=2x+10     /subtract 10 
y=2x  
It is  y=kx.  Here  k=2   -  it is example of direct variation.

Next:
y=2(x+5)
y=2*x + 2*5
y=2x+10
It is not  y=kx  (because you've got +10). So it isn't. 

Next:
y+5=2(x+5)
y+5=2x+10   /subtract 5
y=2x+5
It isn;t too, because you've got  +5.

Next:
y=x+5   isn't, because you've got +5. 

So only first equation

Answer:

y + 10 = 2(x + 5)

Step-by-step explanation:

Direct variation is a mathematical relationship between any two variables which can be expressed by equation in which one of the variable is equal to a constant times of the other variable.

So, y  = kx

where k is any number.

Considering A as:

y + 10 = 2(x + 5)

Solving,

y = 2x ,  this is a direct variation.

Considering B as:

y = 2(x + 5)

Solving,

y = 2x + 10,  this is not a direct variation.

Considering C as:

y + 5 = 2(x + 5)

Solving,

y = 2x + 5,  this is not a direct variation.

Considering D as:

y = x + 5, this is not a direct variation.

We appreciate your participation in this forum. Keep exploring, asking questions, and sharing your insights with the community. Together, we can find the best solutions. IDNLearn.com is committed to providing the best answers. Thank you for visiting, and see you next time for more solutions.