Answer:
Since the sum of the angles is 180 degrees and each angle is represented by the respective algebraic expressions, then to find the value of x, just add the expressions up, set that sum equal to 180, and solve for x. So, (2x-7)+(x+25)+(3x+12)=180 is our equation. Now we just simplify and solve for x.
(2x-7)+(x+25)+(3x+12)=180
6x+30=180 b/c 2x+x+3x=6x and -7+25+12=30.
6x=150 subtract 30 from both sides of the equation
x=25.
Explanation:
Hope this helps!