A) (2а - 3b)(5a+b) -10(a+b)^2 =
= 10a^2 +2ab -15ab -3b^2 - 10(a^2 +2ab + b^2) =
= 10a^2 -13ab - 3b^2 - 10a^2 - 20ab - b^2=
= -33ab -4b^2
б) (-3x^2 y3)^3 * (-2x^5y)^2 =
= (-3 *3 x^2 y^1 )^3 * (-2^1 * x^5 * y^1)^2 =
= (-9)^(1*3) * x^(2*3) * y (1*3) * (-2)^(1*2) * x^(5*2) * y^(1*2) =
= -729x^6 y^3 * 4x^10y^2 =
= -2916 x^(6+10) y^(3+2) =
= - 2916 x^16 y^5
если в условии опечатка:
(-3x^2 y^3)^3 * (-2x^5y)^2 =
= -27x^6 y^9 * 4x^10 y^2 =
=- 108x^16 y^11
A) x +xy -xz = x(1+y -z)
B) x^2 - 9y^2 +x -3y = (x^2 - (3y)^2 ) + (x - 3y) =
= (x+3y)(x-3y) + 1*(x-3y) = (x-3y) (x+3y+1)