Đáp án:
$1)
a) x^2y^3\left ( 1-\dfrac{1}{2}x^2y^5 \right )\\
b) ab(ab^3+a^2-c)\\
c)
xyz(xy+yz+xz)\\
2)
a) 4000\\
b) 2580$
Giải thích các bước giải:
$1)
a) x^2y^3-\dfrac{1}{2}x^4y^8\\
=x^2y^3\left ( 1-\dfrac{1}{2}x^2y^5 \right )\\
b) a^2b^4+a^3b-abc\\
=ab(ab^3+a^2-c)\\
c)
x^2y^2z+xy^2z^2+x^2yz^2\\
=xyz(xy+yz+xz)\\
2)
a) 37.80+41.40-40.15\\
=40(37.2+41-15)\\
=40.100\\
=4000\\
b) 25,8.24+258.7,6\\
=\dfrac{258}{10}.24+258.\dfrac{76}{10}\\
=\dfrac{258}{10}.(24+76)\\
=\dfrac{258}{10}.100\\
=2580$
