What are the roots if the equation #4(x^2-1)= -3x#?

1 Answer
El,
Mar 31, 2017

x= # ( -3 +- sqrt73) / 8#

Explanation:

# 4 * ( x^2 - 1) = - 3x #
# 4x^2 - 4 = -3x #
# 4x^2 + 3x - 4 = 0 #
Which follows the form of: #ax^2 + bx + c =0 #

So you solve it using the discriminant

# Δ= b^2 - 4 * a * c #
# Δ = 9 + 64 = 73 #
Δ > 0 so it has two different solutions

x1= # ( -b + sqrtΔ ) / (2 * a)#
x1= # ( -3 + sqrt73) / 8#

x2= # ( -b - sqrtΔ ) / (2 * a) #
x2= # ( -3 - sqrt73) / 8#

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