Verified answer

(x+5)(2a+1)+(x+5)(3a-8)= (x+5)(2a+1+3a-8)= (x+5)(5a-7)

(5m-3)(n+1)-(2n+3)(3-5m)= (5m-3)(n+1)+(2n+3)(5m-3)= (5m-3)(n+1+2n+3)=(5m-3)(3n+4)

(2a-b)(3a+11)+(5a-11)(b-2a)=(2a-b)(3a+11)-(5a-11)(2a-b)=(2a-b)(3a+11-5a+11)=(2a-b)(22-2a)=2(2a-b)(11-a)

Verified answer

a) (x + 5)(2a + 1) + (x + 5)(3a - 8) = (x + 5)(2a + 1 + 3a - 8) = (x + 5)(5a - 7)

б) (5m - 3)(n + 1) - (2n + 3)(3 - 5m) = (5m - 3)(n + 1) + (2n + 3)(5m - 3) =

= (5m - 3)(n + 1 + 2n + 3) = (5m - 3)(3n + 4)

в) (2a - b)(3a + 11) + (5a - 11)(b - 2a) = (2a - b)(3a + 11) - (5a - 11)(2a - b)

= (2a - b)(3a + 11 - 5a + 11) = (2a - b)(22 - 2a) = 2(2a - b)(11 - a)