Answer:
The unknown number is 12.
Step-by-step explanation:
Let the unknown number be 'x'
Given:
A number increased by 5 is equivalent to twice the same number decreased by 7.
So, 'x' increased by 5 means add 5 to 'x'. This gives [tex]x+5[/tex]
Now, [tex]x+5[/tex] is equivalent to twice of 'x' decreased by 7.
Twice of 'x' means 2 times of 'x' which is [tex]2x[/tex]
'2x' decreased by 7 means subtract 7 from '2x'. This gives,
[tex]2x-7[/tex]
Now, [tex]x+5[/tex] and [tex]2x-7[/tex] are equivalent meaning they are equal. So,
[tex]x+5=2x-7\\5+7=2x-x\\12=x\\x=12[/tex]
Therefore, the unknown number is 12.