The ABC angle is 35 degrees less than the OBA angle. Find these angles if together they are 120 degrees.

Let’s solve this problem using the equation.
Let the degree measure of the angle OBA is equal to x degrees, then the degree measure of the angle ABC is equal to (x + 35) degrees. We know that these angles are 120 degrees together. Let’s make the equation:
x + x + 35 = 120;
x + x = 120 – 35;
x + x = 85;
x * (1 + 1) = 85;
x * 2 = 85;
x = 85: 2;
x = 42.5 degrees – the degree measure of the OBA angle;
42.5 + 35 = 77.5 degrees – the degree measure of the angle ABC.
Answer: 42.5 degrees; 77.5 degrees.