Find the True Equations

In this challenge you will be given a list containing equations, with each equation written as a string. Here's an example:

["1+1=2", "2+2=3", "5*5=10", "3/3=1"]

If you do the math, you'll see that the equations "1+1=2" and "3/3=1" are actually true while "2+2=3" and "5*5=10" are false nonsense.

Write a function which, given a list of equations as above, returns only the true equations. For instance, for the example above the output should be:

["1+1=2", "3/3=1"]

Examples

true_equations(["2*2=4"]) ➞ ["2*2=4"]

true_equations(["1+1=3", "3-1=1"]) ➞ []

true_equations(["1+1=2", "2+2=3", "5*5=10", "3/3=1"]) ➞ ["1+1=2", "3/3=1"]

Notes

• If all equations are false, return the empty list [], as in the second example.
• The equations will only involve the elementary operations: +, -, *, /