Ineed finding the lowest term for -8/9+11/15

Describe the 2 algebraic methods you can use to find the zeros of the function f(t)=-16t^2+400.

Joel wants to buy a new tablet computer fram a store having a 20% off sale on all tablets. the tablet he wants has an original cost of $190. he also wants to make sure he has enough money to pay the 5% sales tax. part one joel uses the incorect expression 0.95(190)(0.8) to calculate that the tablet will cost him a total of $144.40. describe his error and write the correct expression part two how much will joel pay for the tablet show your work if you answer this question correctly you will receive a prize of 99 points good luck

When i'm with my factor 5, my prodect is 20 .when i'm with my addend 6' my sum is 10.what number am i