find the area of a rectangle with length 3a^5b^7c and wudth 5a^4b^3c^3.

To find the area of a rectangle, we need to multiply the length by the width.

Length: 3a^5b^7c
Width: 5a^4b^3c^3

Area = Length x Width (3a^5b^7c)(5a^4b^3c^3)

To multiply the terms, we add the exponents for each variable.

Area = 15a^(5+4)b^(7+3)c^(1+3)
= 15a^9b^10c^4

Therefore, the area of the rectangle with length 3a^5b^7c and width 5a^4b^3c^3 is 15a^9b^10c^4.