Question

How do you solve $3x+9=-27$?

Answer 1

Rearrange the terms of the given equations by leaving the terms containing the variable ‘x’ in the L.H.S. and take the constant terms to the R.H.S. Now, apply simple arithmetic operations like: addition, subtraction, multiplication and division whichever needed, to simplify the equation. Find the value of ‘x’ to get the answer.

Complete answer:
We have been provided with the equation: - $3x+9=-27$ and we are asked to solve this equation. That means we have to find the value of x.
As we can see that the given equation is a linear equation in one variable which is ‘x’, so now leaving the terms containing the variable x in the left - hand side (L.H.S.) while taking all the constant terms to the right - hand side (R.H.S.), we get,
$\Rightarrow 3x=-27-9$
Taking (-1) common in the R.H.S., we get,

& \Rightarrow 3x=-1\times \left( 27+9 \right) \\\ & \Rightarrow 3x=-1\times \left( 36 \right) \\\ & \Rightarrow 3x=-36 \\\ \end{aligned}$$ Dividing both the sides with 3, we get, $$\Rightarrow \dfrac{3x}{3}=\dfrac{-36}{3}$$ Cancelling the common factors on both the sides, we get, $$\Rightarrow x=-12$$ Hence, the value of x is -12. **Note:** One may note that we have been provided with a single equation only. The reason is that we have to find the value of only one variable, that is x. So, in general if we have to solve an equation having ‘n’ number of variables then we should be provided with ‘n’ number of equations. Now, one can check the answer by substituting the obtained value of x in the equation provided in the question. We have to determine the value of L.H.S. and R.H.S. separately and if they are equal to our answer is correct.