[tex]\displaystyle 2.88\cdot(0.5x+1)=7\frac15\\\\\displaystyle\frac{288}{100}\left(\frac5{10}x+1\right)\frac{36}{5}\\\\\displaystyle\frac{72}{25}\cdot\frac{x+2}{2}=\frac{36}{5}\big|\cdot50\\\\72(x+2)=360\\\\\displaystyle x+2=\frac{360}{72}\\\\x+2=5\\x=3[/tex]
