49⁵·7¹²/343⁷= (4/7)⁶·(1 3/4)⁴=

1)49^5*7^12/343^7=7^10*7^12/7^21=7^22/7^21=7 2)(4/7)^6*(1 3/4)^4=(4/7)^6*(7/4)^4=(4^6*7^4)/(7^6*4^4)=4^2/7^2=16/49