Question

pls solve this PLEASEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE

Answer 1

Answer:

Here's the answer to the 12th and 13th question, hope it helps

Answer 2

Answer:

12) 3x+5y=11

xy =2

$9 {x}^{2} + 25 {y}^{2} = ( {3x + 5y)}^{2} - 30xy$

${11}^{2} -3 0 \times 2$

=121-60

=61

13)

${x}^{2} + \frac{1}{ {x}^{2} } = 18$

(1)

${(x + \frac{1}{x}) }^{2} = {x}^{2} + \frac{1}{ {x}^{2} } + 2$

${xx + \frac{1}{x}) }^{2} = 18 + 2$

=20

(2)

${(x - \frac{1}{x}) }^{2} = {x}^{2} + \frac{1}{ {x}^{2} } - 2$

${(x - \frac{1}{x}) }^{2} = 18 - 2$

=16

14)

$14x = {47}^{2} - {33}^{2}$

$14x = (47 - 33)(47 + 33)$

$14x = 14 \times 80$

x=80

15)

(1)

$x - \frac{1}{x} = 3$

${x}^{2} + \frac{1}{ {x}^{2} } = {(x + \frac{1}{x}) }^{2} - 2$

${x}^{2} + \frac{1}{ {x}^{2} } = {(3)}^{2} - 2$

${x}^{2} + \frac{1}{ {x}^{2} } = 7$