input: Write a function to evaluate a given numerical expression in string format and return the result. The function should use the `eval` function to compute the result.
  assert eval_expr("2+3*4-6/2")==11
  assert eval_expr("10-5*2+3")==3
  assert eval_expr("8/4+2*3")==8
  assert eval_expr("7+3-5*2")==0
  assert eval_expr("4*2-6/2+3")==8
output: def eval_expr(expression):
      return eval(expression)