Question

What is the quantity of x in the equation x squared-13x+30=0

Answer 1

You mean: \[x^{2}-13x+30\] right?

Answer 2

use the formula :
x1 + x2 = -b/a

in this case,
a = 1 and b = -13

Answer 3

If so then: Factor it to get
(x-10)(x-3)
Then x=10 and 3.