Which equations are in standard form? Check all that apply

1) y = 2x + 5
2) 2x + 3y = –6
3) –4x + 3y = 12
4) y = (3/2)x – 9
5) (1/2)x + 3 = 6
6) x – y = 5
7) 5x + 3y = (1/2)

Question and answers are in the attached picture. you so much in advance.

Aformual for 8 bottles of window cleaner calls for 6 cups of rubbing to customers alcohol 2 1/4 gallons of water and 1 1/2 cups of ammonia alcohol would the forula call if a factory made 1,280 bottles for stores to sell to customers

The equation x2 – 1x – 90 = 0 has solutions {a, b}. what is a + b?