Question

(2x + 5)³ = 8 (x - 1)³​

Answer 1

Answer:

$we \: \: will \: \: use \: \: one \: \: identity \\ (x + y {)}^{3} = {x}^{3} + {y}^{3} + 3xy(x + y) \\ (x - y {)}^{3} = {x}^{3} - {y}^{3} - 3xy(x - y) \\ (2x + 5 {)}^{3} = 8(x - 1 {)}^{3} \\ (2x {)}^{3} + (5 {)}^{3} + 3 \times 2x \times 5(2x + 5) = 8( ( {x})^{3} - (1 {)}^{3} - 3 \times x \times 1(x - 1)) \\ 8 {x}^{3} + 125 + 30x(2x + 5) = 8( {x}^{3} - 1 - 3x(x - 1)) \\ 8 {x}^{3} + 125 + 60 {x}^{2} + 150x = 8( {x}^{3} - 1 - 3 {x}^{2} + 3x) \\ 8 {x}^{3} + 125 + 60 {x}^{2} + 150x = 8 {x}^{3} - 8 - 24 {x}^{2} + 24x \\ 8 {x}^{3} - 8 {x}^{3} + 125 + 8 + 60 {x}^{2} + 24 {x}^{2} + 150x - 24x = 0 \\ 133 + 84 {x}^{2} + 126x = 0 \\ 84 {x}^{2} + 126x + 133 = 0 \: \: \: \: answer$

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