Respuesta :
Question :-
- Seven times the opposite of a number is 50 less than 3 times the number. What is the number?
Explanation :-
- Let the number be " x. "
According to the question, it's given –
Seven times the opposite of a number is 50 less than 3 times the number.
We've assumed that the number is x. So, opposite of the number will be -x.
[tex]\qquad[/tex][tex]\pink{ \bf \longrightarrow 7(-x) = 3x-50} [/tex]
Now, let's solve this equation –
[tex]\qquad[/tex][tex] \bf \longrightarrow 7(-x) = 3x-50 [/tex]
[tex]\qquad[/tex][tex] \sf \longrightarrow -7x = 3x -50[/tex]
Subtract 3x from both side –
[tex]\qquad[/tex][tex] \sf \longrightarrow -7x -3x = 3x -50-3x [/tex]
Cancel 3x from right side –
[tex]\qquad[/tex][tex] \sf \longrightarrow -7x -3x =\cancel{ 3x} -50-\cancel{3x }[/tex]
[tex]\qquad[/tex][tex] \sf \longrightarrow -10x = -50[/tex]
Now, cancel (-) sign from both side –
[tex]\qquad[/tex][tex] \sf \longrightarrow \cancel{-}10x = \cancel{-}50[/tex]
[tex]\qquad[/tex][tex] \sf \longrightarrow 10 x = 50[/tex]
Then, divide both sides by 10 –
[tex]\qquad[/tex][tex] \sf \longrightarrow \dfrac{10x}{10} = \dfrac{50}{10}[/tex]
[tex]\qquad[/tex][tex] \sf \longrightarrow \dfrac{\cancel{10}x}{\cancel{10}} = \cancel{\dfrac{50}{10}}[/tex]
[tex]\qquad[/tex][tex]\pink{ \bf \longrightarrow x = 5 }[/tex]
- Henceforth, the number will be 5.
Answer: The number is 5
Creating an Equation:
First, we will need to write a mathematical equation that represents the problem.
-> If n is our number, then the opposite of n is -n because -1 times -n is n and -1 times n is -n
-> The underlined portion becomes a part of our equation in the next line.
Seven times the opposite of a number is 50 less than 3 times the number
7 * -n is 50 less than 3n
7 * -n is 3n - 50
7(-n) = 3n - 50
Solving for the Number:
7(-n) = 3n - 50 =|= Our equation
-7n = 3n - 50 =|= Distribute the 7 into -n
-10n = -50 =|= Subtract 3n from both sides of the equation
n = 5 =|= Divide both sides of the equation by -10
Our number is 5