Question

For the system shown below, what are the coordinates of the solution that lies in quadrant II? x^2+4y^2=100 4y-x^2=-20 PLEASE HELP FAST!!!!!

Answer 1

well equate them then solve

\[x^2 + 4y^2 = 100\]

and \[x^2 = 4y + 20\]

so substituting the 2nd equation into the 1st you get

\[4y + 20 + 4y^2 = 100\]

which can be written as

\[4y^2 + 4y - 80 = 0\]

divide each term by 4

and you get

\[y^2 + y - 20 =0\]

now solve for y

Answer 2

(y+5)(y-4)

Answer 3

so y is -5 or 4

Answer 4

Now what??? @campbell_st????

Answer 5

ok... so for the 2nd quadrant... you'll need to positive y

so substitute it into either equation, and use the negative x answer for the ordered pair

Answer 6

thank you!!!!