a+b+c=47.
if we simplify and combine like terms, we will get 5x^2 - 30x + 90.
it will then = 5(x^2 - 6x)+90
if we simplify the parenthesis, it will be 5[(x-3)^2 - 9] + 90. notice how I added the - 9 because -3 * -3 = 9.
Then, I'll multiply and distrubute the 5 to the -9, which is -45
If we combine like terms, the final will be 5(x-3)^2 + 45. 5-3+45=47.