The total area is 407.4262m²
6.4 ounces.
You can get this by first converting to ounces which is a smaller value. Then you can divide by 10.
To convert a decimal to a percent simply just move the decimal point two places to the right and add the percent sign;
0.007 = 0.7%
Hope that helps:D
If, for example, you had x on one side and x on the other, then subtracting x from both sides "disappears" x. If no other power of x shows up on either side, then your equation either has no solution or is always true.