this one is confusing

Answer:
see explanation
Step-by-step explanation:
given
2x ÷ 4 = 10 or
[tex]\frac{2x}{4}[/tex] = 10 ( multiply both sides by 4 )
2x = 40 ( divide both sides by 2 )
x = 20
-------------------------
(b)
He may have mistaken the ÷ for a - (subtraction sign )
2x - 4 = 10 ( add 4 to both sides )
2x = 14 ( divide both sides by 2 ), leading to
x = 7 ← the incorrect answer he obtained