Question

Помогите плизз!!!!!!!
$(3 + 7x)^{2} - x \leqslant - 26 + x(49x - 8)$
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Answer 1

$\boxed{\ (a+b)^2=a^2+2ab+b^2\ }\\\\\\(3+7x)^2-x\leq -26+x(49x-8)\\\\9+42x+49x^2-x\leq -26+49x^2-8x\\\\9+41x\leq -26-8x\\\\41x+8x\leq -26-9\\\\49x\leq -35\\\\x\leq -\dfrac{35}{49}\\\\x\leq -\dfrac{5}{7}\\\\x\in \Big(-\infty ;-\dfrac{5}{7}\ \Big)$