Equation : (7x-4)+(3x-3)+(x) = 180
In the equation the sum of the internal angle in the triangle is 180 degrees. Use this equation to figure the sum of angle in any quadrilateral 180*(number of sides-2)
Solve the equation
Put all similar variable on one side
7x+3x+x-4-3=180
11x-7=180
11x=180+7
11x=187
x = 187/11
x = 17
Now find the angles by plugging in x
Angle F (7*17-4) = 115 degrees
Angle G (x) = 17 degrees
Angle E (3*17-3) = 48 degrees
If you add 115+48+17 you will get a sum of 180 this shows your answer is right
Angle F = 115
Angle G = 17
Angle E = 48
In your question where as the amount of gasoline that 80 drivers bought to fill their cars gas tanks is shown in your diagram and the problem as to find how many drivers bought more than 12 gallons and the best answer would be 36. I hope you are satistfied with my answer and if you need some clarification, please feel free to ask for more
