Respuesta :

konrad509
[tex]\sum_{k=4}^8(2k+2)=2\cdot4+2+2\cdot5+2+2\cdot6+2+2\cdot7+2+2\cdot8+2\\ \sum_{k=4}^8(2k+2)=10+12+14+16+18\\ \sum_{k=4}^8(2k+2)=70[/tex]