I'm not good at math but I have an idea I got 1.71
I took the parenthesis away and put 7x+3 2 = 9 2
subtracted 49x to 7x and got -42x
I put -42x+9=81
subtracted 9 on both sides and got 72
divided -42x÷-42 = 72÷-42
And then I got -1.71 but I don't know so yeah
