Processing Math: Done
Solution 2.1:2b
From Förberedande kurs i matematik 1
We expand the first product of bracketed terms by multiplying each term inside the first bracket by each term from the second bracket
1+1
15x−5x
1−5x
15x=1+15x−5x−75x2
As for the second expression, we can use the conjugate rule
22−(5x)2
=3(4−25x2)=12−75x2
All together, we obtain