A bag contains 77 coins consisting of quarters and nickels. The total value of the coins is $12.50. Write a system of equations that can be used to determine the number of quarters, x, and the number of nickels, y, in the bag. a x + y = 77 0.25x + 0.5y = 12.5 b 0.25x +0.5 y = 77 x + y = 12.5 c x + y = 77 0.25x + 0.05y = 12.5 d 0.25x + 0.05y =77 x + y = 12.5

A

Step-by-step explanation:

because the answer needs both amounts of money and the beginning equation x + y = 77 can't have any other numbers.

answer: standard form is ax^2 + bx + c = 0

step-by-step explanation:

standard form is ax^2 + bx + c = 0

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

distribute to get into standard form

2x^2 - 4x + x - 2 = 0

2x^2 - 3x - 2 = 0

a = 2, b= -3, c = -2

a is your answer

step-by-step explanation: