18.5 - 6 = 12.5 gallons empty
12.5 / 18.5 = 0.676
0.676 x 100 = 67.6%
Answer: 67.6%
Answer: 7.3 x 10^1 & 4400000.
Step-by-step explanation: Count the place holders and just add zeros to the exponential amount.
42.1% of 375.4.....turn percent to decimal...." of " means multiply
0.421(375.4) = 158.0434.....so it would be B. 158.04
P=2l+2w
W=7+3l
So substitute into the original equation
P=2l + 2(7+3l)
78=2l +14 + 6l
-14 -14
—————-
64=8l
8=length
W=7+3l
= 7+3(8)
=7+24
=31
Check your work
Perimeter=8+8+31+31
=78
Hope this helps