The measure of angle ABD is represented by 6y 1.The measure of angle DBC is represented by 4y-7.

Question

The measure of angle ABC is represented by 9y 3.Find the value of y and the measures of angles ABD, DBC, and ABC. Show your work for credit.

Answer 1

I do see a minus sign between 4y and 7, However, I don't see any arithmetic operation signs between the 6y and 1, and between the 9y and 3.