9. Please help besties

Or user elpink25

1

Step-by-step explanation:

 The method I used is elimination.

 x - 2y = 1

-x - 4y = -7         To find y, we need to cancel the x by using it's opposite. This also affects the other numbers in the equation. This makes positive 4 into a negative and positive 7 into a negative.

   Now we are left with,   -2y = 1

                                           -4y = -7

   Add and you get,         -6y = -6

   Divide      -6y/-6     =  -6/-6

      Our answer is, y = 1.

center= (-2,0)

radius= sqrt2/2

step-by-step explanation:

#15. square

step-by-step explanation:

because quadrilatural (idk how to spell it) means somthing that is not 3d or like, equal sides (or somthing like that   you know what i meanz)

hope this halps!

bai!