There are x giraffes at the zoo. the number of elephants is 4 less than three times the number of giraffes, and there are more than 23 elephants.

Greeting homo sapien. I'm assuming you're trying to find the number of giraffes. First we got to establish the variables.
X = # of giraffes
Y = # of elephants
Now let's write the equations
Equation #1
Y = 3X + 4
Now I'm also assuming you meant to write there are 23 more elephants than giraffes, so it would look like this.
Y = X + 23
Now just substitute Y's so you creat an equation with X being the only variable.
X + 23 = 3X + 4
Simplify
2X = 19
X = 9.5
So APPARENTLY there are 9.5 giraffes not sure how to get half a giraffe bt oh well.