Can a denominator be negative in rational number?

The perimiter of a rectangle is 70 inches the legneth of the rectangle is 5 less than 3 times the width of the rectangle what is the width of the rectangle

Can someone check if i did this correct. it’s number 4 if you’re wondering.

Use the quadratic formula to solve the equation. if necessary, round to the nearest hundredth. x^2 - 23 = 10x a. -1.93, 11.93 b. 1.93, -11.93 c. 1.93, 11.93 d. -1.93, -11.93