Answer:
x = 45
Step-by-step explanation:
0.4 + x(10%) = 4.9 . . . . . . given
x(10%) = 4.5 . . . . . . . . . subtract 0.4
x = 45 . . . . . . . . . . . . multiply by 10
_____
10 × 10% = 100% = 1
