Question

Нужно B1 и B2 сроооочно
плачу 70 баллов

Answer 1

$1) 3^{4x+5} =81\\3^{4x+5} =3 ^{4} \\4x+5=4\\4x=4-5\\4x=-1\\x=-0.25\\\\3 ^{4*(-0.25)+5} =3 ^{2} ^{-1+5} =3 ^{4} =81$

$2)x- \sqrt{2 x^{2} -9x+5} =3\\- \sqrt{2 x^{2} -9x+5} =3-x \\ \\ \left \{ {{(- \sqrt{2 x^{2} -9x+5})^{2} =(3-x)^{2}/(1)} \atop {3-x \geq 0}/(2)} \right.$

$(1)2 x^{2} -9x+5=9+ x^{2} -6x\\2 x^{2} -9x+5-9- x^{2} +6x=0\\ x^{2} -3x-4=0\\D=9+16=25\\ \sqrt{D} =5 \\ x_{1} = \frac{3+5}{2} = \frac{8}{2} =4\\ x_{2} = \frac{3-5}{2} = \frac{-2}{2} =-1\\\\(2)3-x \geq 0\\-x \geq -3/*(-1)\\ x \leq 3$
$x=-1$