NCERT Exemplar Solutions
Class 7 - Mathematics - Unit 1: Number System - Multiple Choice Questions
Question 19

Question.  19

\((–43)\times(–99)+43\) is equal to

(a)

4300

(b)

–4300

(c)

4257

(d)

–4214

Detailed Answer with Explanation:

Step 1: Understand the signs
A negative × a negative = a positive.

((-43) imes(-99) = +(43 imes 99))

Step 2: Multiply 43 by 99 (break 43 into 40 and 3)

(43 imes 99 = (40+3) imes 99)

(= 40 imes 99 ;+; 3 imes 99)

(= 3960 ;+; 297)

(= 4257)

Step 3: Now add the extra +43

(( -43) imes( -99) + 43 = 4257 + 43)

(= 4300)

Answer: 4300  ⇒  option (a)

NCERT Exemplar Solutions Class 7 – Mathematics – Unit 1: Number System – Multiple Choice Questions | Detailed Answers