ex acord 10 puncte dau coroana

[tex]a = ({7}^{2} - {2}^{3} \times 5) \times 4 - 11[/tex]
[tex](49 - 8 \times 5) \times 4 - 11 \\ = (49 - 40) \times 4 - 11 = \\ = 9 \times 4 - 11 = \\ = 36 - 11= \\ = 25 = {5}^{2} = > a \: este \: patrat \: \\ perfect[/tex]
[tex] {8}^{50} + {8}^{51} = {8}^{50} + {8}^{50} \times {8}^{1} = \\ = {8}^{50} \times 1 + {8}^{50} \times 8 = \\ = {8}^{50} \times (1 + 8) = {8}^{50} \times 9 = \\ = ( {8}^{25} \times 3 ) ^{2} = > este \\ patrat \: perfect[/tex]
a = ( 7 ^ 2 - 2 ^ 3 × 5 ) × 4 - 11
a = ( 49 - 8 × 5 ) × 4 - 11
a = ( 49 - 40 ) × 4 - 11
a = 9 × 4 - 11
a = 36 - 11
a = 25 = 5 ^ 2 => a = pătrat perfect
b = 8 ^ 50 + 8 ^ 51
b = 8 ^ 50 + 8 ^ 50 × 8 ^ 1
b = 8 ^ 50 × 1 + 8 ^ 50 × 8
b = 8 ^ 50 × ( 1 + 8 )
b = 8 ^ 50 × 9
b = ( 8 ^ 25 × 3 ) ^ 2 => b = pătrat perfect