Answer:
1
Step-by-step explanation:
Given: 15 decreased by six times a number is -9.
Lets assume the number be "x".
Now, putting the value in the equation to get the number.
six times a number = 6x
Then, 15 decreased by six times a number= [tex](6x-15)[/tex]
Now, [tex](6x-15)= -9[/tex]
Adding both side by 15
⇒ [tex]6x= -9+15[/tex]
⇒ [tex]6x= 6[/tex]
Cross multiplying
∴ x= [tex]\frac{6}{6} = 1[/tex]
Hence, the required number is 1.
Next subtituting the value in equation to check.
[tex](6x-15)= -9[/tex]
⇒ [tex](6\times 1-15)= -9[/tex]
⇒[tex](6-15)= -9[/tex]
∴ [tex] -9= -9[/tex]
