Question

решите пожалуста !
а),б),в),г),д),е)

Answer 1

$a);2sqrt5-sqrt{125}+3sqrt{80}=2sqrt5-sqrt{25cdot5}+3sqrt{16cdot5}=\=2sqrt5-5sqrt5+12sqrt5=9sqrt5\\b);sqrt6cdot7sqrt{54}=7sqrt{6cdot54}=7sqrt{324}=7cdot18=126\\c);(sqrt{162}-10sqrt2)cdotsqrt2=(sqrt{81cdot2}-10sqrt2)cdotsqrt2=\=(9sqrt2-10sqrt2)cdotsqrt2=(-sqrt2)cdotsqrt2=-2\\d);(3sqrt{98}-sqrt{128}):sqrt2=(3sqrt{49cdot2}-sqrt{64cdot2}):sqrt2=\=(21sqrt2-8sqrt2):sqrt2=13sqrt2:sqrt2=13$

$e);4sqrt{5t}-frac34sqrt{80t}-12sqrt{frac{125t}9}=4sqrt{5}-frac34sqrt{16cdot5t}-frac{12}3sqrt{25cdot5t}=\=4sqrt{5t}-4cdotfrac34sqrt{5t}-4cdot5sqrt{5t}=4sqrt{5t}-3sqrt{5t}-20sqrt{5t}=\=-19sqrt{5t}$