Question

Aratati ca numarul a=2(1+2+3+...+224)-224 este patrat perfectsi apoi calculati radical din a

Answer 1

$2 \times (1 + 2 + 3 + .... + 224) - 224 \\ 2 \times (224 \times 225 \div 2) - 224 \\ 2 \times ( \frac{224 \times 225}{2} ) - 224 \\ 2 \times( \frac{50400}{2} ) - 224 \\ 2 \times 25220 - 224 \\ 50400 - 224 \\ 50176 \\ \sqrt{50176} = \sqrt{ {224}^{2} } = 224$