How do you solve the system of equations 8x-9y=15 and −x+4y=1 by combining the equations.

What are the soultion(s) to the quadratic equation 40- x^2=0

Express in the simplest form: (x^2+9x+14/x^2-49) / (3x+6/x^2+x-56)

Luke started a weight-loss program. the first week, he lost x pounds. the second week, he lost pounds less than times the pounds he lost the first week. the third week, he lost 1 pound more than of the pounds he lost the first week. liam started a weight-loss program when luke did. the first week, he lost 1 pound less than times the pounds luke lost the first week. the second week, he lost 4 pounds less than times the pounds luke lost the first week. the third week, he lost pound more than times the pounds luke lost the first week.