(1)(4x-3y)^2 (2)(1.5a-2/3b)^2 (3)(25x^3+15^2-20x)÷(-5x) (4)(2/5y^3-7y^2+2/3y)÷2/3y(5)(8a^3b-5a^2b^2)÷4ab (6)(2a)^3×b^4÷12a^3b^2 (7)(6/5a^3x^4-0.9ax^3)÷3/5ax^3越快越好,

(1)(4x-3y)^2=16 x^2-12xy+9 y^2
(2)(1.5a-2/3b)^2 =9/4 a^2-ab+4/9 b^2
(3)(25x^3+15^2-20x)÷(-5x)=-5 x^3+4 x^2-45
(4)(2/5y^3-7y^2+2/3y)÷2/3y=3/5 y^2-21/2 y

(1)(4x-3y)^2
=16x^2-24xy+9y^2
(2)(1.5a-2/3b)^2
=2.25a^2-2ab+4/9b^2
(3)(25x^3+15^2-20x)÷(-5x)
=5(5x^3+45-4x)÷(-5x)
=(5x^3+45-4x)÷(-x)
=-5x^2 -5/x +4
(4)(2/5y^3-7y^2+2/3y)÷2/3y
=y(2/5y^2-7y+2/3)÷2/3y
=(2/5y^2-7y+2/3)*3/2
=3/5y^2-21/2y+1
(5)(8a^3b-5a^2b^2)÷4ab
=2a^2-5/4ab
(6)(2a)^3×b^4÷12a^3b^2
=8a^3×b^4÷12a^3b^2
=2/3b^2
(7)(6/5a^3x^4-0.9ax^3)÷3/5ax^3
=ax^3(6/5a^2x-9/10)÷3/5ax^3
=(6/5a^2x-9/10)*5/3
=2a^2x-3/2

(1)(4x-3y)^2 =(4x)²-2×4x×3y+(3y)²=16x²-24xy+9y² (2)(1.5a-2/3b)^2=2.25a²-2ab+4b²/9 (3)(25x^3+15x^2-20x)÷(-5x) =25x^3÷(-5x) +15x^2÷(-5x) -20x ÷(-5x) =-5x²-3x+4 ...