Answer
x = 21
HOS = 68
Explanation
The arrows beside x point to 12 and 6, which is a straight angle. Straight angles always add up to 180 degrees.
So that means 3x+5 plus 5x+7 must equal 180 degrees.
3x+5+5x+7 = 180
Combine like terms.
8x+12 = 180
Subtract 12 from both sides.
8x = 168
x = 21
But BE CAREFUL.
The problem is asking for the angle HOS.
To do this, just substitute what you got for x into the expression.
3(21)+5 = 68
The value of HOS is 68 degrees.
