Using substitution how do you solve -4x+y=6 -5x-y=21

Steve wants to develop a way to find the total cost of any item including sales tax. the sales tax in his city is 6%. his friend jenna writes the expression x + 6x where x is the cost of the item. explain whether her expression is correct based on the situation.

2y= 3 2 x−2 y = − 1 3 x + 1 y=− 3 1 x+1

Evaluate the discriminant of each equation. tell how many solutions each equation has and whether the solutions are real or imaginary. x^2 + 4x + 5 = 0