If a=1/x+1/y, what is the value of 1/a

 1/a = xy/(y-x)

Step-by-step explanation:

Simplify the reciprocal:

 1/a = 1/(1/x -1/y) = 1/((y-x)/(xy))

 1/a = xy/(y-x)

the answer is a i belaeve atleast thats what my calculator just gfave me

step-by-step explanation:

b. y = 4x - 2

step-by-step explanation:

to find a parallel equation to an equation, make sure both equations have the same slope but different y-intercepts.

y = 4x + 1

4 = slope

1 = y-intercept

y = 4x - 2

4 = slope

-2 = y-intercept

they both have the same slope but different y-intercepts, so, b. is the correct answer.

and to check your work, you can graph both equations. : )