7 times a number is 18 less than the square of that number. find the positive solution

Question

quadratic word problems

Answer 1

Let x = the number:

7x = x² - 7

x² - 7x - 7 = 0 solve using the quadratic formula:

(7 +/- sqrt(49+28))/2 = (7 +/- sqrt(77))/2