What is the opposite of negative seven?

Apositive number a or the same number a increased by 50% and then decreased by 50% of the result?

What are the solutions of the system? y = x^2 + 2x +3y = 4x - 2a. (-1, -6) and (-3, -14)b. (-1, 10) and (3, -6)c. no solutiond. (-1, -6) and (3, 10)

Credit card a offers an introductory apr of 3.4% for the first three months and standard apr of 15.7% thereafter,