Answer:
Part 1)
![(10x+15y)^(2)=(6x+9y)^(2)+(8x+12y)^(2)](https://img.qammunity.org/2020/formulas/mathematics/high-school/4ywfsy1pvjflwor3tt5tq3li9vheriyueo.png)
Part 2) The answer in the procedure
Explanation:
Part 1)
we know that
Applying the Pythagoras Theorem
![c^(2)=a^(2)+b^(2)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ipopn0dndgzoywacpkehydfdusw5okjgav.png)
we have
![c=(10x+15y)](https://img.qammunity.org/2020/formulas/mathematics/high-school/sdxsiu99bddfvr5qn46n34qc5wk9i7hauq.png)
![a=(6x+9y)](https://img.qammunity.org/2020/formulas/mathematics/high-school/obfa1sbcvb8q2rzs1mw5a66366ryizn6ti.png)
![b=(8x+12y)](https://img.qammunity.org/2020/formulas/mathematics/high-school/rqggugscd53qghh24kiemryph7m2x7elry.png)
substitute the values
![(10x+15y)^(2)=(6x+9y)^(2)+(8x+12y)^(2)](https://img.qammunity.org/2020/formulas/mathematics/high-school/4ywfsy1pvjflwor3tt5tq3li9vheriyueo.png)
Part 2) Transform each side of the equation to determine if it is an identity
![(10x+15y)^(2)=(6x+9y)^(2)+(8x+12y)^(2)\\ \\100x^(2)+150xy+225y^(2)=36x^(2)+54xy+81y^(2)+64x^(2)+96xy+144y^(2)\\ \\100x^(2)+150xy+225y^(2)=100x^(2)+150xy+225y^(2)](https://img.qammunity.org/2020/formulas/mathematics/high-school/a5o79p5t1i2yusbw6jchduohmftizxm48i.png)
The left side is equal to the right side
therefore
Is an identity