What are the solutions to the system of equations?

answers:

(−1,−4) and (4.5,11)

(0.5,3) and (9,20)

(4.5,11) and (−1,0)

(4.5,6.5) and (−1,0)

the third option is correct

Step-by-step explanation:

The system of equations are

y = 2x^2 - 5x - 7 - - - - - - - - - - -1

y = 2x + 2 - - - - - - - - - - - - - 2

We would equate equation 1 and equation 2. It becomes

2x^2 - 5x - 7 = 2x + 2

2x^2 - 5x - 2x - 7 - 2 = 0

2x^2 - 7x - 9 = 0

We would find two numbers such that their sum or difference is -7x and their product is - 18x^2. The two numbers are 2x and - 9x. Therefore

2x^2 + 2x - 9x - 9 = 0

2x(x + 1) - 9(x + 1) = 0

2x - 9 = 0 or x + 1 = 0

2x = 9 or x = - 1

x = 9/2 = 4.5

Substituting x = 4.5 or x = -1 into equation 2, it becomes

y = 2 × 4.5 + 2 or y = 2 × - 1 + 2

y = 11 or y = 0

Therefore, the solutions are

(4.5, 11) (- 1, 0)