You cannot add 3x and 1. You can add 3x and x and get 4x though.
When you add a negative number, the one on the right side gets cancelled out. E.g. -3x + - 3x = -3x
7x-40 = -3x Add 40 and add 3x to both sides:- 7x-40+40+3x = 3x-3x+40 10x = 40 Divide both sides by 10:- x = 4
You cannot add them. The 'y' in the 4xy means that you cannot add it to 3x, since the 'y' is an extra component that the 'x' does not have. You can add 3x to 3x, or 4y to 4y, but you cannot add terms which contain different variables to each other. (It's like trying to add apples and oranges, they're not the same thing).
3x-7+4 = 42 3x-7 = 38 3x = 45 x=15
3x + 4 = 4x - 5 Add 5 to both sides: 3x + 9 = 4x Subtract 3x from both sides: 9 = x
3x - 4 = 17 3x = 21 (add 4 to both sides) x = 7 (divide both sides by 3)
-2 -3x = 10 Add 2 to both sides: - 3x = 12 Divide both sides by -3: x = -4
Yes and they add up to 11x
You can just add them together. The answer is 9x.