How do you find the vertex of 2x^2+12x-5

Aschool had an election where the candidates received votes in the ratio 1: 2: 3. if the winning candidate received 210 votes, how many total people voted in the election?

Bob paid $3 less than tim at a local pizza parlor. together they spent $7.80. how much did bob pay for pizza?

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?