I got the same answer as you. Try to ask your teacher about it since it’s a math problem online or something.
Since you subtract 6 and you have to find the sixth term, you can do:
-6×5=-30 ( negative shows you're subtracting and since 75 is the first term, then you have to find the difference of the input/term 6-1, the sixth term minus the first)
75-30=45
You can check by actually continuing the pattern.
75,69,63,57,51,45,39......
Hey what number do you need help with
2(x+7)3X
I think... look it up though to be sure

- subtract the 12 from both sides so that it becomes the last constant term in the quadratic equation which should now equal 0.
- take the 4x
- half the coefficient of 4 (2)
- square it (4)
- add it to the equation (+4)
- subtract it from the equation (-4)
- factorise the square (x+2)^2 expands to (x^2 + 4x + 2) as {a+b}^2={a^2 + ab + ba + b^2}
- now the equation is in turning point form.
- to find x, add 16 and square root 16 and (x+2)
- subtract 2 from positive or negative 4 (as -4^2 and 4^2 both equal 16).
- This should give you two values for x, -6 and 2.
I really hope that this helped :)