Answer:
7^-5
Step-by-step explanation:
7^4.7^-9
when multiplying the same base, add the powers
7^4+(-9)
7^4-9
c cause it says length = 5x
15,300 + 18750 + 13,500 + 23,400 +19500 = 90,450
divide all the numbers by 100, then multiplying by 3
