Question

Pls i need this today help me

Answer 1

Explanation:

a) 4x² + 20 = 0

4x² = -20

x² = -20/4

x² = -5 = i² *5

x = √i²5

x = i√5

b) 4x² + 5 = -7

4x² = -7 - 5

4x² = - 12

x² = -12/4

x² = -3 = 3i²

x = i√3

c) x² + 4x + 20 = 0

a = 1 ; b =4 ; c =20

`x = \frac{-b+\sqrt{b^(2)-4ac}}{2a} and \frac{-b-\sqrt{b^(2)-4ac}}{2a};\\\\x = (-4+√(16-4*1*20))/(2*1) and(-4-√(16-4*1*20))/(2*1)\\\\=(-4+√(16-80))/(2) and (-4-√(16+80))/(2)\\\\=(-4+√(-64))/(2) and (-4-√(64))/(2)\\\\= (-4+8i)/(2) and(-4-8)/(2)`

= (-2 +4i) & -12/2

= (-2 + 4i) and (-6)