Question

repede!Am nevoie de ajutor!!​

Answer 1

Ai răspuns atașat pe foaie.

Answer 2

Explicație pas cu pas:

41.a)

$(1 + 2 + 3 + ... + 36) \div ( - 18) = \frac{36 \times 37}{2 \times ( - 18)} \\ = \frac{36 \times 37}{ - 36} = - 37$

b)

$( - 1 - 2 - 3 - ... - 25) \div ( - 26) = \\ = - (1 + 2 + 3 + ... + 25) \div ( - 26) \\ = \frac{25 \times 26}{2 \times 26} = \frac{25}{2}$

42.

$\{\left[{( - 6)}^{2} + {2}^{3}\right]\times ( - 4) - \left[( - 6) + {( - 3)}^{2} \right]\} \div ( - 11) =$

$= \left[(36 + 8) \times ( - 4) - ( - 6 - 27) \right] \div ( - 11)$

$= \left[44 \times ( - 4) - ( - 33) \right] \div ( - 11)$

$= ( - 176 + 33) \div ( - 11)$

$= ( - 143) \div ( - 11) = 13$

43.

$36 \div \{\left[{( - 3)}^{3} + 2\right] \div ( - 5) + \left[( - 18) \div {( - 3)}^{2} \right]\} =$

$= 36 \div \left[( - 27 + 2) \div ( - 5) + ( - 18 \div 9) \right]$

$= 36 \div \left[( - 25) \div ( - 5) + ( - 2) \right]$

$= 36 \div (5 - 2) = 36 \div 3 = 12$

44.a)

${( - 1)}^{1} \cdot {( - 1)}^{2} \cdot {( - 1)}^{3} \cdot\cdot...\cdot {( - 1)}^{20} =$

$= {( - 1)}^{1 + 2 + 3 + ... + 20} = {( - 1)}^{210} = 1$

b)

${( - 1)}^{1} + {( - 1)}^{2} + {( - 1)}^{3} + ... + {( - 1)}^{20} =$

$= ( - 1) + 1 + ( - 1) + 1 + ... + ( - 1) + 1$

$= ( - 1 + 1) + ( - 1 + 1) + ... + ( - 1 + 1)$

$= 0 + 0 + ... + 0 = 0$