5 + 4 • (8 - 6)2 = 5 + 4 • (2)2 = 5 + 4 • 4 = 5 + 16 = 21
Use distance formula
=√(3-3)^2 +(-4-4)^2
=√64
=8
You formatted the equation wrong for the setting your calculus on i would recommend using a Ti-34
Answer:
The fifth line contains the error.
Step-by-step explanation:
Line 1 is the equation.
Lines 2, 3, and 4 are correct.
The error is in the 5th line.
The square root of a negative number is not a real number, so if this problem is solved only with real numbers, there is no solution.
If imaginary numbers are allowed, then the last line should read:

7 * 38 + 3*45 - 56
use order of operations
(7*38) + (3*45) - 56
266 + 135 - 56
=345