I would reccomend the app photo math its really easy to use and it answers questions like this.
Answer:
x=8
Step-by-step explanation:
start by setting angle a equal to angle b
next add 21 to the opposite side
then subtract 2x from the opposite side
finally you're left with x=8
Move over 2 decimal places
This would be 38.4%
Answer:
He walks the distance to his house from school twice, hope this helps!! (:
X=Distance
x*2