Question 1210382
<pre>

Solve: 45x + 30 = 120
x = 12
x = 10
x = 6
x = 2

I think that this student may have only gotten to the stage of finding
solutions by trial and error by substitution.

      Try x = 12
   45x + 30 = 120
45(12) + 30 = 120
   540 + 30 = 120
        570 = 120, so x = 12 is NOT the correct answer.

      Try x = 10
   45x + 30 = 120
45(10) + 30 = 120
   450 + 30 = 120
        480 = 120, so x = 10 is NOT the correct answer.

      Try x = 6
   45x + 30 = 120
 45(6) + 30 = 120
   270 + 30 = 120
        300 = 120, so x = 6 is NOT the correct answer.

      Try x = 2
   45x + 30 = 120
 45(2) + 30 = 120
    90 + 30 = 120
        120 = 120, so x = 2 IS the correct answer.

Edwin</pre>