Which expression is positive

What value of x will make the triangles similar by the sss similarity theorem?

While scuba diving, rajeev dove to a depth of 12.6 feet below the surface of the water and then descended another 8.7 feet. what expression can be used to find rajeev's new position? 12.6 – 8.7 –12.6 – 8.7 –12.6 – (–8.7) 12.6 – (–8.7)

What is the 12th term of b(n)=-4-2(n-1)