Select the equation below that shows the correct setup to solve for the length of side BC in the triangle above.
• 9^2+x^2=7^2
• 9^2 + 7^2=x^2
• 7^2 -x^2=9^2
• x^2 - 7^2= 9^2
• 7^2 + x^2= 9^2
