Arturo is building a flower bed in the shape of a right triangle. the hypotenuse of the right triangle is 13 feet. one of the legs needs to be 7 feet longer than the other leg. which equation can be used to find x, the length of the shorter leg? x(x + 7) = 13 x(x + 7) = 169 x2 + (x + 7)2 = 13 x2 + (x + 7)2 = 169

For this case what we should do is use the Pythagorean theorem.
 We have then:
 c ^ 2 = a ^ 2 + b ^ 2
 Where,
 c: hypotenuse
 a, b: sides of the triangle. 
 Substituting values we have:
 13 ^ 2 = x ^ 2 + (x + 7) ^ 2
 Rewriting we have:
 x ^ 2 + (x + 7) ^ 2 = 169
  
 An equation that can be used to find x, the length of the shorter leg is:
 x ^ 2 + (x + 7) ^ 2 = 169

The formula should follow a²+b²=c²

Answer x² + (x+7)² = 169