Question

Am nevoie de ajutor la astea doua exerciții dau coroana ​

Answer 1

Explicație pas cu pas:

$x = \sqrt{ \frac{19}{2,(1)} } + \sqrt{ \frac{20}{2,(2)} } + \sqrt{ \frac{21}{2,(3)} } + ... + \sqrt{ \frac{26}{2,(8)} }=\\ = \sqrt{ \frac{19}{ \frac{21 - 2}{9} } } + \sqrt{ \frac{20}{ \frac{22 - 2}{9} } } + \sqrt{ \frac{21}{ \frac{23 - 2}{9} } } + ... + \sqrt{ \frac{26}{ \frac{28 - 2}{9} } }\\ = \sqrt{ \frac{ \not19 \cdot 9}{\not19}} + \sqrt{ \frac{\not20 \cdot 9}{\not20}} + \sqrt{ \frac{\not21 \cdot 9}{\not21}} + ... + \sqrt{ \frac{\not26 \cdot 9}{\not26}} \\= \underbrace{\sqrt{9} + \sqrt{9} + \sqrt{9} + ... + \sqrt{9}}_{8} \\= \underbrace{3 + 3 + 3 + ... + 3}_{8} = 8 \cdot 3 = 24$

q.e.d.