$A = _{}$ $(-\cfrac{1}{2}$$x^{2}$$y^{})$ . $(\cfrac{14}{5}$$x^{}$$y^{3}$$z^{3})$
a) $A = _{}$ $(-\cfrac{1}{2}$.$\cfrac{14}{5})$ . $(x^{2}$. $x^{})$ . $(y^{}$ . $y^{3})$ . $z^{3})$
= $-\cfrac{7}{5}$$x^{3}$$y^{4}$$z^{3}$ (bậc 10)
b) Tại x = 1 ; y = 1 ; z = 2, ta có:
$A = _{}$ $-\cfrac{7}{5}$$x^{3}$$y^{4}$$z^{3}$
= $-\cfrac{7}{5}$$.1^{3}$$.1^{4}$$.2^{3}$
= $-\cfrac{7}{5}$$.1^{}$$.1^{}$$.8^{}$
= $-\cfrac{56}{5}$
Chúc bn học tốt!
Mong bn cho mik ctlhn và vote 5* ah