So : [tex]12+ \frac{\sqrt{35}}{2} + \frac{12-2 \sqrt{35} }{2} [/tex]?
First, you want to bring everything together on the top of the fraction.
12=24/2 so you can have [tex] \frac{24+ \sqrt{35}+12-2 \sqrt{35} }{2} [/tex]
Add like terms -- 12 +24 = 36 [tex] \sqrt{35}-2 \sqrt{35} = \sqrt{35} [/tex]
Now we are at [tex] \frac{24+ \sqrt{35} }{2} [/tex] Which is the lowest possible simplified version while remaining at exact value.
Feel free to check my math! I kinda did this off the top of my head.