Question

Find $x$. $(x) + 3699 + 1985 - 2047 = 31111$.
A) $3478$
B) $27474$
C) $30154$
D) $27574$

Answer 1

Hint: Here first of all we will assume any unknown variable “x” instead of question mark and then will move all the terms in the opposite side making the required term as the subject and simplifying for the required value.

Complete step by step solution:
Take the given expression:
Let us assume the unknown term as “x”
$x + 3699 + 1985 - 2047 = 31111$
Move all the constants on the opposite side. When you move any term from one side to another then the sign of the terms also changes. Positive term becomes the negative term and the negative term becomes positive term.
$x = 31111 - 3699 - 1985 + 2047$
Here, we will apply the DMAS rule which suggests that we should add terms first and then perform subtraction. So, above equation can be re-written as –
$x = \underline {31111 + 2047} - 3699 - 1985$
Add first two terms in the above equation –
$x = 33158 - 3699 - 1985$
Now, simplify the first two terms in the above expression on the right hand side of the equation.
$
  x = \underline {33158 - 3699} - 1985 \\
  x = 29459 - 1985 \\
 $
Find the resultant value calculating the difference of the terms in the above expression.
$x = 27474$
Hence, from the given multiple choices the option B is the correct answer.

Note:
Be careful about the sign convention while simplifying the terms in the equation. When you move any term from one side to another then the sign of the terms also changes. Positive term becomes negative and the negative term becomes the positive term. According to the DMAS rule, first Division, multiplication, addition and subtraction are applied. Remember and be careful about the sign convention.