I need help with this question for my math hw. Please Help!

9514 1404 393

  1. 2x +2y = 310; x -y = 55

  2. y = 50, x = 105

Step-by-step explanation:

Let the numbers be represented by x and y. Double the numbers would give 2x and 2y. We're told the sum of the doubled numbers is 310, so one equation is ...

  2x + 2y = 310

The difference of the numbers is (x-y). We're told that difference is 55, so the other equation is ...

  x - y = 55

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We can divide the first equation by 2, and subtract the second.

  1/2(2x +2y) -(x -y) = 1/2(310) -(55)

  2y = 100 . . . . . . . simplify

  y = 50 . . . . . . . . . divide by 2

  x -50 = 55   ⇒   x = 105 . . . . use the second equation to find x

The two numbers are 105 and 55.

guess at question:

a vertical line intersects the graph of g(x,y) = 0 at two points. what conclusion follows about the function f(x) implicitly defined by g(x,f(x)) = 0?

the domain of f(x) cannot include the x coordinate of any such vertical line.

informally, f(x) is not a function, and

g(x,y)=0 cannot be solved for y uniquely.

the relation r = {(x,y) such that g(x,y) = 0} is a function if

for all (a,b) ∊ r and (c,d) ∊ r, a=c implies b=d.

step-by-step explanation: