3(d+2)-12 = d-2
3d +6 -12 = d - 2
3d-d = 12 - 6 - 2
2d = 4
d = 2
I think it’s (7x^5) + (-1x^5 + 9x)
The answer is 10. If you replace the number letters with the numbers you get 6 + 10 / 2 - 1. Then you follow PEMDAS, so first divide 10 with 2 to get five (6 + 5 - 1). Add 6 and 5 to get 11 and subtract 1 to get the final answer of 10.
The number that is being multiplied by the variable ( the letter) so like if you have 2X the 2 is the coefficient
