0\\+ + + (-4)- - - - (\frac{1}{4})+ + + + \\x\in (-\infty.-4)U(\frac{1}{4},+\infty)\\b)\;\;t(t+3)>0\\+ + + + (-3)- - - (0)+ + + +\\t\in (-\infty.-3)U(0,+\infty)\\c)\;\;b^2 \leq 16\\b^2-16 \leq 0\\(b-4)(b+4) \leq 0\\+ + + + [-4]- - - - [4]+ + + +\\x\in [-4,4]\\d)\;\; x^2+4x+3 \leq 0\\x_1=-3,\;x_2=-1\\+ + + [-3]- - - [-1]+ + + +\\x\in [-3,-1]" alt="a)(x-\frac{1}{4})(x+4)>0\\+ + + (-4)- - - - (\frac{1}{4})+ + + + \\x\in (-\infty.-4)U(\frac{1}{4},+\infty)\\b)\;\;t(t+3)>0\\+ + + + (-3)- - - (0)+ + + +\\t\in (-\infty.-3)U(0,+\infty)\\c)\;\;b^2 \leq 16\\b^2-16 \leq 0\\(b-4)(b+4) \leq 0\\+ + + + [-4]- - - - [4]+ + + +\\x\in [-4,4]\\d)\;\; x^2+4x+3 \leq 0\\x_1=-3,\;x_2=-1\\+ + + [-3]- - - [-1]+ + + +\\x\in [-3,-1]" align="absmiddle" class="latex-formula">