Question

Solve the following system of equations and show all work. y = 2x^2 y = –3x −1

Answer 1

Answer:(- 1/2, 1/2)

(- 1, 2)

Step-by-step explanation:

The given system of equations is expressed as

y = 2x²- - - - - - - - - - - - - - -1

y = - 3x - 1- - - - - - - - - -- - - -2

We would apply the method of substitution by substituting equation 1 into equation 2. It becomes

2x² = - 3x - 1

2x² + 3x + 1 = 0

We would find two numbers such that their sum or difference is 3x and their product is 2x². The two numbers are 2x and x. Therefore,

2x² + 2x + x + 1 = 0

2x(x + 1) + 1(x + 1) = 0

2x + 1 = 0 or x + 1 = 0

x = - 1/2 or x = - 1

Substituting x = - 1/2 into equation 1, it becomes

y = 2(-1/2)² = 1/2

Substituting x = - 1 into equation 1, it becomes

y = 2(-1)² = 2