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