Question

Zapisz jak najprościej 2a(b-3) - 2b(a-3) a(a+b)+a(a-b)+b(b+a)+b(b-a) 5a(a-2)+2a(a+5) 3(a+2b-3c)-2(4-2c)+5(c-b)-(a+b)

Answer 1

2a(b-3)-2b(a-3)=2ab-6a-2ab+6b=-6a+6b

a(a+b)+a(a-b)+b(b+a)+b(b-a)=a²+ab+a²-ab+b²+ab+b²-ab=2a²+2b²

5a(a-2)+2a(a+5)=5a²-10a+2a²+10a=7a²

3(a+2b-3c)-2(4-2c)+5(c-b)-(a+b)=3a+6b-9c-8+4c+5c-5b-a-b=2a-8

Answer 2

2a(b-3) -2b(a-3) = 2ab -6a -2ba +6b = 2ab - 2ab  -6a +6b = -6a +6b

 

a(a+b) +a(a-b) +b(b+a) +b(b-a) =

a^2 +ab +a^2  -ab +b^2 +ba +b^2-ba= 

2a^2 + 2ab -2ab  +2b^2 = 2a^2 +2b^2

 

5a(a-2) +2a(a+5)= 5a^2 -10a +2a^2 +10a = 7a^2 -10a +10a = 7a^2

 

3(a +2b -3c) -2(4 -2c) +5(c -b) - (a +b) =

3a +6b -9c -8 +4c +5c -5b -a -b =

3a - a +6b -6b -9c +9c  -8 = 2a -8