Since this is an absolute value equation, it will have two answers. For the first answer, take away the absolute value bars and solve 3x + 1 = 2. Subtract 1 from both sides to get 3x = 1 and divide each side by 3 to get x = 1/3. Now onto the second solution. This time, take away the absolute value bars and make the other side of the equation, the 2, negative, to get 3x + 1 = -2. Now solve this by subtracting 1 from each side to get 3x = -3 and divide each side to get the other answer which is x = -1. The answer is x = -1 or 1/3, hope this helps!
3. Credit Card: (1842.66 - 250) (.145/12) = $19.24
Savings: 250(0.04/12) = $0.83
Difference = 19.24 - 0.83 = $18.41
4. Credit Card: (1842.66 - 500) (.145/12) = $16.22
You will save $18.41 - $16.22 = $2.19 by putting all $500 toward the higher credit card rate.
2 - b.
3 - a.
I'm not sure about 4. Hope this helps!