Which first step for solving the given system using substitution results in an equation wit 3x+y = 9
5x- 3y = 1

Solve the system of equations. y= 2x y= x^2 - 15

At $1.32 million, they closed last month percent above what they paid in 2007." how much did they pay in 2007?

Hell . what are the solutions to `10x^2 - 38x - 8 = 0`? is this when i find the factors and use the numbers within the factors to determine the zeros? i hope that made sense lol