If g (x) = 2x2 + bx + 5 and g (1) = 4, what is the value of g (-1) ?

Substitute for the values of x and then, solve the equation so using one another.

I am going to assume that this is a polynomial equation and "2x2" means 2 to the 2nd power judging by the use of g (x) by tendencies of math teachers.

If this is the case:

g (1) = 2 (1 * 1) + 1b + 5 = 2 + 1b + 5 = 1b + 7

If g (1) = 4, then 1b + 7 = 4.

1b + 7 = 4

Subtract 7 from both sides

1b = - 3

b = - 3

g (-1) = 2 (-1 * - 1) + - 1b + 5 = 2 - 1b + 5 = - 1b + 7

Now substitute b for "-3" and you will get - 1 (-3) + 7 = 3 + 7 = 10.

g (-1) will equal 10.