I would use a small, easy slope.
Answer:
Number 4
Step-by-step explanation:
Side-Angle-Side, it has to be between the two sides.
7x+(x-4)(X+5)-5x
7x+(X*2+ 5x-4x-20)-5x
7x+(X*2+ x-20)-5x
X*2+3x-20
I believe the equation should be set up like this: 85 + 5x + 5x + 5x - 10 + 5x + 5 = 540. Don't forget to combine like terms! Please let me know by sending me a message if you need any more help :)