NCERT Exemplar Solutions
Class 7 - Mathematics - Unit 1: Number System - Problems and Solutions
Question 127

Question. 127

127. Let \(u,v,w,x\) be integers with \(u=-4\) and \(x\neq1\). Given

\(u\times v = u\),   \(x\times w = w\),   \(u + x = w\).

Find (a) \(v\), (b) \(w\), (c) \(x\).

Answer:

(a) 1

(b) 0

(c) 4

Detailed Answer with Explanation:

From \(u\times v=u\) with \(u\neq0\) ⇒ \(v=1\). From \(x\times w=w\) ⇒ \(w( x−1)=0\). Since \(x\neq1\), \(w=0\). Then \(u+x=w\Rightarrow −4+x=0\Rightarrow x=4\).

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