Algebra 2 problem for 10 points (multiples answers) unit#10?

Question

1 the graph of which equation is a circle

a 5x^2+10x=9+5y^2

b 5x^2-10x=0-5y^2

c 5x^2+5x+y^2=9

d 5x^2+10x+5y=9

2 solve the system of equations by graphing x^2+y^2=16 and y=-X-4

a (4,0),(0-,4)

b (0,-4),(-4,0)

c (-4,0),(0,-4)

d (0,4),(4,0)

Answer 1

Problem 1:

B.  This can be simplified into (x-1)^2 + (y-0)^2 = 1

     The other ones cannot be factored into perfect squares.

{ A. cannot be a circle because y^2 would be negative if moved over to the side with x^2.  C. cannot be a circle as x^2 and y^2 do not have the same coeficient.  D. cannot be a circle because there is no y^2.}

Problem 2:

B & C (are the same thing).  You can solve this one algebraically by substituting (-X-4) for "Y" in the first equation, or you can just graph the two equations and analyzed it visually.

Answer 2

1.a&b

2.you ,please, draw the graph yourself,as it is not possible to

show this here.

the solution is (b);

Hope it will help.

Answer 3

1. b

2.  b