Question

Please answer these question with question number

Answer 1

One small request friend next time onwards when you post a doubt with a lot of questions kindly increase the points as I could have answered other questions in the time I answered yours and earned more points. Thank you in advance and hope my answer helps you.

Answer:

21. 4

22. 16

23. 4

24. -4, 1/2

25. 117

26. 1

27. 55°

28. 54/99

29. 9

Step-by-step explanation:

21.  (3 + √5)(3 - √5)    [(a + b)(a - b) = a² - b²]

==> (3)² - (√5)²

==> 9 - 5

==> 4

22.  $(16)^{\frac{1}{4}}$ × $\sqrt[4]{16}$

==> (4) × (4)

==> 16

23.  5x - 4x² + 3 at x = -1

==> 5(1) - 4(1)² + 3

==> 5 - 4 + 3

==> 4

24.  2x^2+7x -4=0

==> 2x^2+8x -x -4=0

==> 2x(x+4)-1(x+4)=0

==> (X+4)(2x -1)=0

==> X+4=0

==> X=-4

==> 2x-1=0

==> X=1/2

The zeroes of the polynomial 2x²+7x-4 are -4 , and 1/2.

25.  Refer Q 25 for picture

==> ∠BOD + ∠BOC = 180° (Linear Pair)

==> ∠BOC = 180° - 63°

==> ∠BOC = 117

26.  2x + 5y = k at x = 3 and y = -1

==> 2(3) + 5(-1) = k

==> 6 - 5 = k

==> 1 = k

27. 70° + 2x = 180° ( Corresponding Linear Pair)

==> 2x = 180° - 70°

==> 2x = 110°

==> x = 55°

28. x = 0.545454...

==> 100x = 54.54545..

==> 99x = 54.54 - 0.54

==> 99x = 54

==> x = 54/99

29. $\frac{6\sqrt{27}}{2\sqrt{3}}$

==> $\frac{6\sqrt{3}\sqrt{9}}{2\sqrt{3}}$

==> $3\sqrt{9}$

==> 3(3)

==> 9