How do you evaluate #-3\sqrt { 7} \cdot 5\sqrt { 7} - \sqrt { 8- ( 2^6\div 2^ { 4} ) }#?

1 Answer
Oct 29, 2017

#-107#

Explanation:

#color(blue)(-3sqrt7*5sqrt7-sqrt(8-(2^6-:2^4))#

Lets solve the right part

When we divide #color(brown)(x^y-:x^z#, we get #color(green)(x^(y-z)#

So,

#rarr-3sqrt7*5sqrt7-sqrt(8-(2^(6-4)))#

#rarr-3sqrt7*5sqrt7-sqrt(8-(2^(2)))#

#rarr-3sqrt7*5sqrt7-sqrt(8-4)#

#rarr-3sqrt7*5sqrt7-sqrt(4)#

#rarr-3sqrt7*5sqrt7-2#

When we multiply two numbers with radical signs, we multiply the first numbers and then multiply it with the product of the numbers in the radical sign

#rarr(-3)(5)(sqrt7)(sqrt7)-2#

#rarr-15*7-4#

#rarr-105-2#

#color(green)(rArr-107#

Hope this helps!!! ☻☺