(1)5a²b÷(-三分之一ab)×2ab²
2个回答

5a²b÷(-1/3ab)×2ab²

=5a²b×(-3ab)×2ab²

=[5×(-3)×2]a^4b^4

=-30a^4b^4

[(x+2y)²-(x+y)(x-y)-5y²]÷2x

=(x²+4xy+4y²-x²+y²-5y²)÷2x

=(4xy)÷2x

=2y

(-3.6×10^10)÷(-2×10²)²

=(-3.6×10^10)÷(4×10^4)

=-0.9×10^6

(2a-b+3)(2a-3+b)

=[2a-(b-3)][2a+(b-3)]

=(2a)²-(b-3)²

=4a²-b²+6b-9