Answer:
Number 4 is a right triangle whether 3 isnt.
Step-by-step explanation:
I just know this because a right triangle is always gonna have a 90 degree angle whether that number 3 doesnt have one
<em>subtract 2 from both sides</em>
<em>divide both sides by (-4)</em>

16/21 is your answer
You can take a 2 out of both numbers to get your answer
I hope this helped! :)