7n + 3 = 3n + 27
7n -3n =27-3
4n =24
n= 6.
-72-4x^2+8x^3-36x/x-3
-4(18+x^2-2x^3+9x)/x-3
-4(-2x^3+x^2+9x+18)/x-3
-4(-2x^2x(x-3)-5x x(x-3)-6(x-3) )/x-3
-4 x(-(x-3) ) x (2x^2+5x+6)/x-3
-4 x (-1) x (2x^2 +5x+6)
8x^2+20x+24
Answer:
The answer would be 1.33 x 
Step-by-step
1.28 x
= 12800
5 x
= 500
12800 + 500 = 13300
13300 = 1.33 x
in scientific notation
Hope this helps:)
Sorry, I got the wrong answer earlier but I fixed it:)
The original expression evaluates to 54.4 as shown in the first working.
_____
For some reason, 3.4 got transcribed to be 1.7 in the 3rd line of the second working. There is no math operation in the expression that requires 3.4 to be divided by 2.