Answer:
janarver 12- mae verdemax x-
Step-by-step explanation:
Easy buddy...
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Step (1)
I choose a number which is x
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Step (2)
Multiplies by 90 :

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Step (3)
Adds up to -23 :

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And we're done.
Thanks for watching buddy good luck.
♥️♥️♥️♥️♥️
Answer:
9 + 10 +x= 21
x=21-19
x=2
add 2 in left hand side to get 21