Question

Explain why the numbers 8x7x6x5x4 +5X4 and 11×13×15+11 are
composite numbes​

Answer 1

(8 × 7 × 6 × 5 × 4) + (5 × 4)

Taking out 5 as a common factor,

5(8 × 7 × 6 × 4) + 5(4)

⇒5 × 1344 + 5×4

⇒ 5 × (1344 + 4)

⇒ 5 × 1348

Since the number has 5, 1348 as it's common factor other than 1, it is a composite number.

11 × 13 × 15 + 11

Taking 11 as common factor,

⇒11(13 × 15 + 1)

⇒11(195 + 1)

⇒ 11(196)

Since, the number has 11 and 196 as it's common factor other than 1, it is a composite number

Answer 2

$QUESTION :$

$Explain\:8×7×6×5×4+5×4\\ and 11×13×15+11 \: composite\: numbers.$

$SOLUTION:$

$COMPOSITE<u> </u><u>NUMBER</u><u>:</u><u>\</u><u>\</u> => The\: number\: which \:have\: more \\ than \: two\: multiples \: are\: known\\ as\: composite\: numbers.$

$First look for 8×7×6×5×4+5×4$

$8 \times 7 \times 6 \times 5 \times 4 + 4 \times 5$

$= > 8 \times 7 \times 6 \times 20 \times 2$

$So\:the \: number \: have \: more \: than \: two \\ factors so \: it \: is \: a \: composit \: number$

$For \: the \: number$

$11 \times 13 \times 15 + 11$

$= > 13 \times 15 \times 11 \times 2$

$this \: number \: also \: have \: more \: than \\ two \: factors \: so \: it \:is \: aslo \: composite \: \\ numbers.......................................$

$hence \: proved$

$hope \: \: it \: help \:$

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