4) Basically the solution for the system of equations is the coordinate where both the lines intersect or cross each other. If you look closely, the point of intersection is at the coordinate (1, -1).
Solution: C) (1, -1)
5) There are many ways to solve the equation given to you. We can complete the square, factor the equation, or use the quadratic formula. For this problem, I would use the quadratic formula because it says to solve the "quadratic" equation.
The quadratic formula is:
x = -b ±√b² - 4ac / 2a
In the equation 8x² + 16x + 8 = 0, your terms are:
a = 8
b = 16
c = 8
Substitute the following into the quadratic formula.
x = -16 ±√(16)² - 4(8)(8) / 2(8)
Simplify the equation.
x = -16 ± √256 - 256 / 16
x = -16 ± √0 / 16
x = -16 / 16
x = -1
Solution: B) -1