What’s the answer to ​9.1x−0.8=−1.71

The triangles are similar. what is the value of x? enter your answer in the box. x = two right triangles. the larger right triangle is labeled x on the longer leg, 12 on the shorter leg and 20 on the hypotenuse. the smaller triangle is labeled 4 on the longer leg, 3 on the shorter leg, and 5 on the hypotenuse.

In the pendulum formula t=2pi. read the problem on the picture ! ; $; $; ! ; ! ; ! ; )$; ! ; ! ; ! ; $; $; $! ; ! ; ); $; $$

Answer this question! 30 points and brainliest! only if you know the answer.