Question

дам 100б помогите пожалуйста .​

Answer 1

$7b(2b+3)-(b+6)(b-5) = 14b^2+21b-(b^2-5b+6b-30) = \\\\ =14b^2+21b-b^2-b+30 = 13b^2+20b+30$

$(3x+4)(4x-3)-5=(2x+5)(6x-7)\\ 12x^2-9x+16x-12-5=12x^2-14x+30x-35\\-9x+16x-12-5=-14x+30x-35\\7x-16x=-35+17\\-9x=-18\\x=2$

$\dfrac{3x-7}{8} - \dfrac{x-3}{6} = 1\quad \quad \quad | * 24\\\\3(3x-7)-4(x-3)=24\\9x-21-4x+12=24\\5x=33\\\\x=\dfrac{33}{5} = 6\dfrac{3}{5} = 6.6$

$24ab+32a-3b-4 = 24\cdot 0.3 \cdot \biggl( - 1\dfrac{2}{3} \biggr )+32\cdot0.3-3 \cdot \biggl( - 1\dfrac{2}{3} \biggr )-4 = \\\\\\ = 24\cdot \dfrac{3}{10} \cdot\biggl(- \dfrac{5}{3} \biggr ) -3 \cdot\biggl(- \dfrac{5}{3} \biggr ) -4 = -24\cdot \dfrac{1}{2} +9.6 +5-4 = \\\\\\ = -12+9.6+5 -4 = -1.4$