Question

determinati numarul real a, stiind ca numerele 24, 1020 si a sunt, in aceasta ordine, termeni consecutivi ai unei progresii aritmetice.

Answer 1

$\displaystyle 24, 1020 , a \\ \\ 1020= \frac{24+a}{2} \\ \\ 14+a=1020\cdot2 \\ 14+a=2040 \\a=2040-14\\a=2026 \\ \text{Daca ni se spune ca 3 numere sunt in progresie aritmetica aplicam:}$