Show workings please

Answer: x = 21°
Step-by-step explanation:
37 + 4x + (3x - 4) = 180° Original Equation
37 + 4x + 3x - 4 = 180° Commutative Property of Addition
7x + 33 = 180° Combine like terms
7x = 148° Subtract 33 from both sides
x = 21° Divide both sides by 7