Answer: x = 6
Explanation
First, add 5.2x on on both sides:
-5.2x + 5.2x + 57.9 = 15.9 + 5.2x + 1.8x
57.9 = 15.9 + 7x
Next, subtract 15.9 on both sides:
57.9 - 15.9 = 15.9 - 15.9 + 7x
42 = 7x
Now, divide by 2 on both side to get x:
42/7 = 7x/7
6 = x
Check your answer:
-5.2(6) + 57.9 = 15.9 + 1.8(6)
-31.2 + 57.9 = 15.9 + 10.8
26.7 = 26.7
Now we are sure that x = 6.