problem on Linux ubuntu installation for iMac

Hello ..

I have problem on Linux ubuntu installation which appears on the first screen after booting from USB .

My desktop computer is :

apple imac
21.5-inch, Late 2009
Processor 3.06 GHz Intel Core 2 Duo

Memory 4 GB 1067 MHz DDR3

Graphics ATI Radeon HD 4670 256 MB

Serial Number W801537HB9U

Software OS X 10.9.5 (13F1507)

See the attachment .

Thank you in advanced .

Attached Images

• IMG_2595-1.jpg (34.3 KB)