Answer:
The value of Y is 5.
Step-by-step explanation:
I am assuming you're asking of this particular question?
If so, start out by creating a theory that if both sides of the triangle are marked as "equal" with one mark, then both angles of B and C should be equal as well. So, in other words, <em>75</em> = <em>(3x)</em>. Or, in more simpler terms, 75 = 75.
With that in mind, we'll now add all angles to equal 180 since this shape is a triangle. 75 + 75 + (4y+10) = 180.
Add similar terms, 150 + (4y+10) = 180.
Subtract 150 from both sides; (4y+10) = 30.
Subtraction Property of Equality (Subtract 10 from both sides); 4y = 20.
Finally, divide both sides by 4. Y = 5.
<em>I hope this helped</em>~♥