Question

4 și 5. Mulțumesc anticipat!
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Answer 1

4. 3(x^2+4x+7)=4(3x+8)+1

3x^2+12x+21=12x+33

3x^2=12

x^2=4=>x=4 sau x= -4

5. (3x+4)^2=(2x+1)^2

9x^2+24x+16=4x^2+4x+1

5x^2+20x+15=0 :5

x^2+4x+3=0

Δ=b^2-4ac=16-12=4=> radical Δ = 2

x1/2= -b±radicalΔ/2a= -4±2/2

x1= -2/2= -1

x2= -6/2= -3