Question

solve this for 50 points

Answer 1

Step-by-step explanation:

35. x - 2y = 13

or, $(x-2y)^{3}$ = $13^{3}$ [Cubing both sides]

or, $x^{3} - (2y)^{3}$ - 3.x.2y ( x - 2y) = 169

or, $x^{3} - 8y^{3}$ - 6*7*13 = 169

or, $x^{3}$ - $8y^{3}$ = 169 + 546

or, $x^{3}$ - $8y^{3}$ = 715 Ans.

36. x +1/x = 7

or, $(x + 1/x)^{2}$ = $7^{2}$ [Squaring both sides]

or, $x^{2} + 1/x^{2}$ + 2 = 49

or, $x^{2} + 1/x^{2}$ = 49 - 2 = 47 Ans i

Again squaring both sides,

$(x^{2}  + 1/x^{2}) ^{2}$ = $47^{2}$

or, $x^{4} +1/x^{4}$ + 2 = 2209

or, $x^{4} +1/x^{4}$  = 2209 - 2 = 2207 Ans ii

38. x - 1/x = 6

or, $(x - 1/x)^{3}$ = $6^{3}$

or, $x^{3} - 1/x^{3}$ - 3.x.1/x ( x - 1/x) = 216

or,  $x^{3} - 1/x^{3}$  - 3 * 6 = 216

or, $x^{3} - 1/x^{3}$ = 216+ 18 = 234 Ans

Answer 2

Answer:

refer to the attachment