Answer:
8x + 3 = 7
Explanation:
By process of elimination you can narrow it down to just 2 answers.
You know that the total number of hours is 7, so the equation must end with "= 7"
And you would want to multiply the time spent on the paintings by the amount of paintings BEFORE adding the extra 3 hours, so it can't be the first answer.
Bonus hint:
x = 0.5
If you want to double check