Help it’s late and i can’t think

The sum of these consecutive integers is equal to 9 less than 4 times the least of the integer. find the three integers

The? half-life of a radioactive substance is 20 years. if you start with some amount of this? substance, what fraction will remain in 120 ? years

One of the complementary angles is 4 degrees mor than the other. find the angles (recall that complementary angles are angles whose sum is 90 degrees.) which of the following can not be used to solve the problem if x represents one of the angles? a. 2x-4=90 b. 2x+4=90 c. x+4=90