Tim's mom filled the gas tank in her suv

For the equation below, x is the input and y is the output. y = -4x + 3 if the input is -8, then the output is

When i add money am i supposed to make it like this 7+12 or 7.00+12.00 because i got 19 dollars for my answer

How many different three-digit numbers can be formed using the digits 1 comma 2 comma 9 comma 6 comma 4 comma 3 comma and 8 without repetition? for example, 664 is not allowed.