Lösung 2.1:2b
Aus Online Mathematik Brückenkurs 1
We expand the first product of bracketed terms by multiplying each term inside the first bracket by each term from the second bracket
As for the second expression, we can use the conjugate rule \displaystyle (a-b)(a+b)=a^2-b^2, where \displaystyle a=2 and \displaystyle b=5x,
All together, we obtain
