Question

a) (x+y)*a+(x+y)*b

b) (m-1)(k-1)+(k-1)(m+1)

c)(a-1)(b+c)-(a-1)(b-c)

Prosze o rozwiązanie zadania, nie same wyniki ;)

Answer 1

 

a)

 

b)

 

c)

Answer 2

a) (x+y)*a+(x+y)*b=x*a+y*a+x*b+y*b=xa+ya+xb+yb = x(a+b)+y(a+b)

 

b) (m-1)(k-1)+(k-1)(m+1)=[m*k+m*(-1)+(-1)*k+(-1)*(-1)]+[k*m+k*1+(-1)*m+(-1)*1]=

    [mk-m-k+1]+[km+k-m-1]=mk-m-k+1+km+k-m-1= 2km-2m

 

c) (a-1)(b+c)-(a-1)(b-c)=[a*b+a*c+(-1)*b+(-1)*c]-[a*b+a*(-c)+(-1)*b+(-1)*(-c)]=

    [ab+ac-b-c]-[ab-ac-b+c]=ab+ac-b-c-ab+ac+b-c= 2ac-2c