Answer the 21st one. this question is from the chapter exponents and powers.

729

Step-by-step explanation:

Move items with negative exponents from numerator to denominator or vice versa and change sign of exponent. Factorize composite numbers, say 10^3 = 2^3 × 5^3 and 81 = 3^4. Combine factors with same base, adding exponents. Cancel factors appearing in both numerator and denominator, subtracting exponents.

5^-3×6^-5×81×4/(3^-7×10^-3)

= 3^7×10^3×81×4/(5^3×6^5)

= 3^7×2^3×5^3×3^4×2^2/(5^3×2^5×3^5)

= 2^5×3^11×5^3/(2^5×3^5×5^3)

= 3^6

= 729

a=r

d=q

c=p

b=s

hope this !

1/2*qr*rs

step-by-step explanation: