I need help on this pls

Let the closed interval [a , b] be the domain of function f. the domain of f(x - 3) is given by (a) the open interval (a , b) (b) the closed interval [a , b] (c) the closed interval [a - 3 , b - 3] (d) the closed interval [a + 3 , b + 3]

Select the lengths in centimeters that would form a right triangle

Yvaries directly as x. y =90 when x=6. find y when x=13