Question

4x² + 7x + 3 = 2x² +2x

Answer 1

Observe só:

$4 x^{2} -2 x^{2} +7x-2x+3=0\\2 x^{2} +5x+3=0\\Delta= b^{2} -4*a*c\\a=2\\b=5\\c=3\\Delta= 5^{2} -4*2*3\\Delta=25-24\\Delta=1\\x= \frac{-b+- \sqrt{Delta} }{2*a} \\\\x= \frac{-5+- \sqrt{1} }{2*2}\\\\x= \frac{-5+-1}{4} \\\\x'= \frac{-5+1}{4} = \frac{-4}{4} = -1\\\\ x''= \frac{-5-1}{4} = \frac{-6}{4} = \frac{-3}{2}$

Answer 2

4x² + 7x + 3 = 2x² + 2x
4x² - 2x² + 7x - 2x + 3 = 0
2x² + 5x + 3 = 0

a = 2; b = 5; c = 3

Δ = b² - 4ac
Δ = 5² - 4.2.3
Δ = 25 - 8.3
Δ = 25 -24
Δ = 1

x = - b +/- √Δ  = - 5 +/- √1
           2a               2.2

x = - 5 + 1 = - 4 = - 1
          4         4

x = - 5 - 1 = - 6  (:2)  =  - 3
          4         4  (:2)        2

R.: x = - 1 e x = - 3
                           2
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