Answer:
20 = x
Step-by-step explanation:
All interiror angles in this triangle will equal 180
Set your formula up as 180 = x+5+7x-5+x then solve for x
180 = x+5+7x-5+x
180 = x + 7x + x +5 - 5
180 - 5 + 5 = 9x
180 = 9x
180 / 9 = x
20 = x
You can check your result by pluging in 20 for all x
180 = 20+5+7*20-5+20
180 = 180
