2√3х-5=7; 2√3х=12; <span>√3х=6; 3х=36; х=12
3х-4=9; 3х=13; х=13/3</span>
- 115а + 13а = (- 115 + 13)а = - 102а
42х⁵ у² 3
-------- * ----------- = ---------------
у⁴ 14х⁵ у²
2/sin22.5/cos22.5 - cos22.5/sin22.5=2cos22.5/sin22.5 - cos22.5/sin22.5=cos22.5/sin22.5=ctg22.5