In math (or English, for that matter), a question is never true or false. Only a statement can have such attributes.
If you make the statement "if A ate many sugar, A will get diabetes," in math it cannot be decided wheter it is true or false without additional information about the truth values of the statements "A ate many sugar" and "A will get diabetes".
You flip the inequality.
Example: if x > -y and you divide both sides by (-1) then you flip the inequality so: -x < y
I don't really speak Spanish but I'll guess that says
How do I solve y = 1 - 2.5
Unless I'm missing something, there's not even any algebra here.
The way we subtract a bigger number from a smaller number is first we subtract the smaller number from the bigger number the regular way, then we prepend a minus sign.
y = 1 - 2.5 = -(2.5 - 1) = -1.5
The probability that the card is a football card is 20 out of 50 or 40%
the probability that the card is a basketball card is 10 out of 50 or 20%