2 3/10 + (-1 1/5) Mixed Numbers to improper fraction

Amanufacturer knows that their items have a normally distributed lifespan, with a mean if 9.1 years, and standard deviation of 2.9 years. if you randomly purchase one item, what is the probability it will last longer than 10 years?

On tuesday, a local hamburger shop sold a combined total of 375 hamburgers and cheeseburgers. the number of cheeseburgers sold was two times the number of hamburgers sold. how many hamburgers were sold on tuesday?

What is the product of (4x + - 5)? a) -8x^2 - 26x - 15 b) -8x^2 + 26x - 15 c) -8x^2 - 26x + 15