A) f(x+1) = 6x^2 + 8x + 6
1) substitute the value of x as (x+1)
2) 2(3(x+1)^2 -2(x+1) +2)
3) 6(x^2 + 2x + 1)
4) 6x^2 + 8x + 6
B) f(3) = 46
1) simplify the expression first
2) 6x^2 -4x + 4
3) Now just substitute 3: 6(3)^2 -4(3) + 4
4) 6•9 - 12 + 4 = 46
I hope this helps :)
