Divide the sale price by the original price:
56 / 89 = 0.7
Multiply by 100:
0.7 x 100 = 70%
The sale price is 70% of the original price, so the discount would be 30% (100-70= 30)
Do you mean how you can tell between an area formula and a volume formula? Well usually like on a reference sheet it says the shape and the letter a or v, a representing area and v representing volume. I hope this helps, if it doesn't please tell me in the comment section
48= l*w
l= 8+w
To solve for width, substitute the value of l in the first equation so that everything is in terms of w.
Final answer: 48= (8+w)*w