Help plz :( Whats 9 + 10?

What kinds of numbers have an odd number of factors?

Will mark brainliest if you answer ! the taco shop sold 198 lunches friday. this number is 3 more than 3 times the number they sold monday. let n represent the number of lunches sold monday. which equation shows an equality between two different ways of expressing the number of lunches sold on friday? a. n – 3 = 198 b. 3n – 3 = 198 c. 3n + 3 = 198 d. n + 3 = 198

The equation x2 – 1x – 90 = 0 has solutions {a, b}. what is a + b?