Step by step explanation thanks

Answer:
Step-by-step explanation:
Let 1st no. be x
increase by 10%
x+x/10=11x/10
now decrease 10%
11x/10-(11x/10)/10=99x/100
the decrease is x-99x/100
x/100
decrease % is 1%
Answer:
$99
Step-by-step explanation:
10% = 10
100-10=90 then add 10% of that
10%=9
90+9=99