By replacing the term "a number" with a variable like x, you can get the equation 7x - x = -48. Then, further simplify the equation by combining like terms to equal 6x = -48. After that, divide both sides by six to get x alone, making your final answer x = -8.
It does not satisfy both because when you plug in the ordered pair on the second problem, it becomes 1=3(2)-1 and when worked out that gives you 1=5 which is untrue.