Question

Kindly Solve this.....

Answer 1

Here's your answer Matey!! :-)

Answer 2

${a}^{3} + 4a - 8 = 0 \\ {a}^{3} + 4a = 8 \: \: \: \: \: ................(1)\\ \\ on \: squaring \: both \: sides \\ \\ {( {a}^{3} + 4a) }^{2} = {8}^{2} \\ {a}^{6} + 16 {a}^{2} + 8 {a}^{4} = 64 \\ \\ on \: multiplying \: both \: sides \: by \: a \\ \\ {a}^{7} + 16 {a}^{3 } + 8 {a}^{5} = 64a$
$on \: adding \: 16 {a}^{3} \: both \: sides$
${a}^{7} + 8 {a}^{5} + 32 {a}^{3} = 16 {a}^{3} + 64a \\ {a}^{7} + 8 {a}^{2} ( {a}^{3} + 4a) = 16( {a}^{3} + 4a) \\ \\ from \: eq \: (1) \\ \\ {a}^{7} + 8 {a}^{2} \times 8 = 16 \times 8 \\ {a}^{7} + 64 {a}^{2} = 128$