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5 votes
Factorise fully 21a - 7a2

User Matt Sach
by
3.7k points

2 Answers

1 vote

Answer: The factors are : 7a , (3-a)

Step-by-step explanation: 21a - 7a2

7×3×a - 7×a×a

= The common factor = 7a

∴7a(3 - a)

The factors are : 7a, (3-a)

User VforVitamin
by
3.9k points
4 votes

In both 21a and 7a^2, we can see that both terms contain an 'a' and a number that is divisible by 7.

7a(3 - a)

Hope this helps! :)

User Igor Peshansky
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3.1k points