Which are the center and radius of the circle with this equation?
x^2 - 4x + y^2 + 2y = 0

Arianna is buying plants for her garden. she buys 15 flowering plants for $96. pink flowering plants sell for $8, and purple flowering plants sell for $5. how many pink flowering plants did arianna buy? i figured out the answer! the answer is 7. 8x +5y = 96 plug in 7 for x 8 (7) + 5y = 96 56 + 5y = 96 subtract 56 from both sides 5y/y = 40/5 y = 8 she bought 7 pink and 8 purple plants

Explain how you can use the associative property to evaluate (7x50)x4.

X2 + y 2 = 36 x + y = 6 solve the system of equations.