Đáp án:
`A=14/9`
`B=-6551/-23914838`
`C=1443/293`
Giải thích các bước giải:
`a, A= (4^6 × 9^5+ 6^9 × 120) / (8^4 × 3^12)`
`A=(4^6*9^5)/(8^4*3^12)+(6^9*120)/(8^4*3^12)`
`A=(2^12*3^12)/(2^12*3^12)+(2^9*3^9*2^3*3*5)/(2^12*3^12)`
`A=1+(2^12*3^10*5)/(2^12*3^10*3^2)`
`A=1+5/3^2`
`A=1+5/9`
`A=9/9+5/9`
`A=14/9`
`___________________________-`
`b,B= (5. 4^15. 9^9- 4.3^26. 8^9) / (7. 2^29 .27^6 -5. 2^29 . 9^16)`
`B=(5*2^30*3^18-2^2*3^26*2^27)/(7*2^29*3^18-5.2^29*3^32)`
`B=(5*2^30*3^18-3^26*2^29)/(7*2^29*3^18-5.2^29*3^32)`
`B=(3^18(5*2^30-3^8*2^29))/(3^18(7*2^29-5*2^29*3^14))`
`B=(5*2^30-3^8*2^29)/(7*2^29-5*2^29*3^14)`
`B=(2^29(5*2-3^8))/(2^29(7-5*3^14))`
`B=(5*2-3^8)/(7-5*3^14)`
`B=(10-6561)/(7-5*4782969)`
`B=(10-6561)/(7-239148)`
`B=-6551/-23914838`
`_____________`
`c)C= (5^10 .7^3 -25^3. 49^2) / (( 125.7)^3+ 5^9 .14^2)`
`C= (5^10 .7^3 -5^6. 7^4) / ( 125^3*7^3+ 5^9 .2^2*7^2)`
`C= (5^10 .7^3 -5^6. 7^4) / ( 5^9*7^3+ 5^9 .2^2*7^2)`
`C= (5^6(5^4 .7^3 - 7^4)) / ( 5^6(5^3*7^3+ 2^2*7^2)`
`C= (5^4 .7^3 - 7^4) / (5^3*7^3+ 2^2*7^2)`
`C= (7^2(5^4*7 - 7^2)) / (7^2(5^3*7+ 2^2)`
`C= (5^4*7 - 7^2) / (5^3*7+ 2^2)`
`C=(625*7-49)/(125*7+4)`
`C=(4375-49)/(875+4)`
`C=4329/879`
`C=1443/293`
