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.
