1. solve using quadratic formula
a) x^2 + 12x - 13 = 0

Anyone know? will mark brainliest if correct

Determine the fraction of total interest owed. after the fourth month of a 12-month loan: the numerator is: {(n + ) + (n + ) + (n + ) + (n + )} = , and the denominator is: {(n) + (n + 1) + + (n + )} = . therefore, the fraction is numerator/denominator (to the nearest tenth) =

Three times the sum of a number and seven is negative thirty-six. what is the number?