1+2+3+14+2n=2080

20+2n=2080

20+2×n=2080

n=1+2+3+4=10

n=2080÷2=1040

n=1040-10

n=1030

1+2+3+14+2n=2080

20+2n=2080

20+2×n=2080

n=1+2+3+4=10

n=2080÷2=1040

n=1040-10

n=1030