9a-3a+4, in other words, 9a subtracted by 3a added in 4. does anyone know the answer?

What expression is equivalent to (2x-1)(x-3)?

The probability that an adult possesses a credit card is .70. a researcher selects two adults at random. by assuming the independence, the probability that the first adult possesses a credit card and the second adult does not possess a credit card is:

Out of $20$ creepy-crawly creatures in a room, $80\%$ are flies and $20\%$ are spiders. if $s\%$ of the total legs belong to spiders, what is $s$?