Class 9th math 1.3 solution english PCTB

Question 1: The sum of three consecutive integers is forty two, find the three integers.

Solution:

Let \(x-1\), \(x\), and \(x+1\) are three consecutive integers

According to the given condition of question

\[\begin{align*} x-1+x+x+1&=42\\
3x&=42\\
x&=\frac{42}{3}\\
x&=14\\
\end{align*}\]

So, \(13\), \(,14\), and \(15\) are required numbers

——– Alternate Method ——–

Let \(x\), \(x+1\), and \(x+2\) are three consecutive integers

According to the given condition of question

\[\begin{align*} x+1+x+x+2&=42\\
3x+3&=42\\
3x&=42-3\\
3x&=39\\
x&=\frac{39}{3}\\
x&=13\\
\end{align*}\]

So, \(13\), \(,14\), and \(15\) are required numbers

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