well from me studing this question i have found the My KeY bOaRd JuSt BrOkE
log₉(<em>x</em> - 7) + log₉(<em>x</em> - 7) = 1
2 log₉(<em>x</em> - 7) = 1
log₉(<em>x</em> - 7) = 1/2
Take the base-9 antilogarithm of both sides; in other words, make both sides powers of 9:

can also be written as √9 = 3, and
, so the equation reduces to
<em>x</em> - 7 = 3
Solve for <em>x</em> :
<em>x</em> = 10
Answer: 20% increase
Step-by-step explanation:
change/ original number
(60 - 50 / 50) x 100 = 20
20%

55+85=140
180-140=40
10x=40
divide by ten on each side
x=4