Question

x²+3x-40=0 by completing squares methord​

Answer 1

Answer:

$x {}^{2} + 3x - 40 \\ x {}^{2} + (8 - 5)x - 40 \\ x {}^{2} + 8x - 5x - 40 \\ x(x + 8) - 5(x + 8) \\ (x + 8)(x - 5) \\ x = - 8 \\ x = 5$

Answer 2

X^2+3x-40=0

By using the method of completing the square

1.take the coefficient of highest power of x common.

2.Add and subract the square of half of new coefficient of x

3. Now you will get perfect square on both sides

4.Now use the identity a^2-b^2=(a+b)(a-b)

5.you will be able to get the roots of the equation as - 8 and 5

For reference image is being attached