A and D show the same level of precision because they both have numbers in the hundredth place.
When you multiply a decimal with a decimal, you just multiply like you would with whole numbers. Then, you count the numbers to the right of the decimal for both multiplicand an multiplier. If the equation was 8.374 x 1.234, then you would put the decimal 6 spots to the left of the product. For the first step of solving this is just multiply like and decimal is not there. The answer would be 10333516. Then you count the number right of the multiplicand and the multiplier. In total there is 6 numbers, so you put the decimal 6 spots to the right. The end result would be 10.333516. Hope this helped!
-x^2 + 4 = 2x + 1
-x^2 - 2x + 4 - 1 = 0
-x^2 - 2x + 3 = 0
(x + 3)(-x + 1)= 0
x + 3 = 0 -x + 1 = 0
x = -3 -x = -1
x = 1
so x = -3 and x = 1
