The score on a trivia game is obtained by subtracting the number of incorrect answer from twice the number of correct answer. If a player answered 50 total question and obtained a score of 40 , how many questions did the player answer correctly?

The player answer correctly 30 questions

Step-by-step explanation:

First we have to develop the information that gives us as 2 equations

x = correct answer

y = incorrect answer

z = score = 40

h = total answer = 50

2x - y = z               x + y = h

2x - y = 40             x + y = 50

we clear the x of one equation and replace the value of x in the other equation

x = 50 - y

2x - y = 40

2(50 - y) - y = 40

100 - 2y - y = 40

-3y = 40 -100

y = -60/-3

y = 20

x = 50 - y

x = 50 - 20

x = 30