The perimeter of a rectangle with width y and length x is 40. Write the width, y,
in terms of its length, X.

y = 20 - x

Step-by-step explanation:

Perimeter of a rectangle = 40 units

2 * ( length + width) = 40

  2* (x + y) = 40    {Divide both sides by 2}}

     x + y = 40/2

     x + y = 20       {Subtract x from both sides}

            y = 20 - x

i think it's ф or x=6,-6

step-by-step explanation:

-x^2=-36

x^2=-36

ф

or

if you mean by : -(x^2)=-36

it'll be: x^2=36

x=6,x=-6

hope it'll ! have a good day!

you for asking!