Rút gọn biểu thức a, x( x - y ) + y( x - y )
b, ( x² - 2xy + y² )( x - y ) - ( x - y )( x² + xy + y²
c, 7x( 4y - x ) + 4y( y - 7x ) - ( 4y² - 7x)
d, ( 2x + y )( 2z + y) + ( x - y )( y - z )

Use the discriminant to describe the roots of each equation. then select the best description. 2m2 + 3 = m double root real and rational roots real and irrational roots non-real roots

Find the difference in area between the circle and the triangle. click on the answer until the correct answer is showing.possible answers: a = 4 pi - 8a = 9 pi - 9/2 √3a = 16/3 pia = 16a = 27 pi

Dana wants to identify the favorite professional baseball team of people in her community. she stands outside a local sporting goods store and asks every other person who enters, "what is your favorite professional baseball team? " will the results of her survey be valid? explain.