If x²+y²=17 and x×y=4 then whats x-y?

The sixth grade art students are making a mosaic using tiles in the shape of right triangles.each tile has leg measures of 3 centimeters and 5 centimeters.i f there are 200 tiles in the mosaic what is the area of the mosaic.

Which of the following is correct interpretation of the expression -4+13

Find the value of the variable and the length of each chord for #5 and #6.