How do you know the correct order on which to evaluate algebraic expressions

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]

What is the equation in slope-intercept form of the linear function represented by the table? y -18 -1 -8 4 2 912 o y=-2x-6 o y=-2x+6 o y=2x-6 o y = 2x+6

Which shows the correct substitution of the values a, b and c from the equation 1=-2x+3x^2+1