54System of two equations
If is the solution to the system above, what is the value of ? A) 4 B) 7 C) 8 D) 10
a + b = 7, which is answer B. Subtracting the equations cancels the 3b terms to give a = 4, then substituting back gives b = 3. Check: 4(4) + 3(3) = 25 ✓.