(5x)pangkat -6 di kali x per 5pangkat -7

(5x)^-6 × x/5^-7
= 5^-6 x^-6 × x/1/5^7
= 1/5^6 x^6 × 5^7x
= 5^7-6 x^6+1
= 5¹ x^7
= 5x^7