Paul split an inheritance between two investments, one paying 7% annual interest and the other 10%. He invested twice as much in the 10% investment as he did in the 7% investment. If his combined annual income from the two investments was $4050, how much did he inherit?

0.07 * (1/3)x + 0.10 * (2/3)x = 4050
--> 0.07x/3 + 0.20x/3 = 4050
--> [Multiply both sides by 3]
--> 0.07x + 0.20x = 12150
--> 0.27x = 12150
--> x = 45000

The original inheritance was $45,000.

Look, when you want to do something like put it like x^2. x2 could mean x² or x₂. so to clear confusion, know the notation. to find the product multiply the x's and you get -8x and the y's and you get 6y. since it's all being multiplied it is just -8x6y, or answer a. although the better answer is -48xy(combining -8 and 6) because you should multiply constants whenever you can.