Answer:

Step-by-step explanation:
Given

Required
Determine x2, y2
Start by splitting the expression
and 
Solving for x2 in 
Multiply through by 2


Make x2 the subject;

Similarly:

Multiply through by 2


Make y2 the subject;

Hence:

Answer:
The number is 523
Step-by-step explanation:
<u><em>The question is English is</em></u>
Number 289 less than 812
Let
x ----> the number
To find out the number subtract 289 from 812
so

therefore
The number is 523
Here is what I got:(maybe wrong) 12*8*3 = 288, which is how big the box is. Then, you remove 1.5 inches from the height and get 10.5*8*3, which is 252. Subtract 252 from 288 to get the answer, 36.