Question

Testul : 2 va rog va dau coronița!

Answer 1

$1)a)5x-2=-7$

$5x=-7+2$

$5x=-5$

$b)4-2.3x=-0.6$

$-2.3x=-0.6-4$

$-2.3x=-4.6 |:(-2.3)$

$x=2$

$c)\sqrt{2}+2x=\sqrt{18}$

$\sqrt{2}+2x=3\sqrt{2}$

$2x=3\sqrt{2}-\sqrt{2}$

$2x=2\sqrt{2}\:|\div2$

$x=\sqrt{2}$

$2)3(x - 3) - 2(1 - x) = 2x - 2(x + 4) + 7$

$3x - 9 - 2 + 2x = 2x - 2x - 8 + 7$

$3x + 2x - 2x + 2x = - 8 + 7 + 9 + 2$

$5x = 10\:|\div\:5$

$x = 2$

$3){(2x-1)}^{2}+4x=-2{x}^{2}+9-8x$

${[2\times(-2)-1]}^{2}+4\times(-2)=-2\times{(-2)}^{2}+9-8\times(-2)$

${(-4-1)}^{2}-8=-2\times4+9+16$

${(-5)}^{2}-8=-8+9+16$

$25-8=17$

$17=17\:(A)$

$4){(x-2)}^{2}-(x-1)(3-2x)=3(x+3)(x-3)+25$

${x}^{2}-4x+4-3x+2{x}^{2}+3-2x=3({x}^{2}-9)+25$

${x}^{2}-4x+4-3x+2{x}^{2}+3-2x=3{x}^{2}-27+25$

${x}^{2}+2{x}^{2}-3{x}^{2}-4x-3x-2x=-27+25-4-3$

$-9x=-9\:|\div(-9)$

$x=1$

$5)\frac{2x-1}{3}+3x-4=\frac{1-2x}{4}-\frac{5}{12}\:|\div12$

$4(2x-1)+36x-48=3(1-2x)-5$

$8x-4+36x-48=3-6x-5$

$8x+36x+6x=3-5+4+48$

$50x=50\:|\div50$

$x=1$

$2+mx-3x=x(3m-2)+4$

$2+m\times1-3\times1=1(3m-2)+4$

$2+m-3=3m-2+4$

$m-3m=-2+4-2+3$

$-2m=3 \:|\times(-1)$

$2m=-3$

$m=-\frac{3}{2}$

$6)|2x+3|\times|x-1|+\sqrt{4{x}^{2}+12x+9}\times|2x-2|=0$

$|2x+3|\times|x-1|+|2x+3|\times|2x-2|=0$

$|2x+3|(|x-1|+|2x-2|)=0$

$|2x+3|=0$

$2x+3=0=>2x=-3=>x=-\frac{3}{2}$

$-2x-3=0=>-2x=3=>x=-\frac{3}{2}$

$|x-1|+|2x-2|=0$

$|x-1|=-|2x-2|$

$I)x-1=-(2x-2)$

$x-1=-2x+2$

$x+2x=2+1$

$3x=3\:|\div3$

$x=1$

$II)x-1=2x-2$

$x-2x=-2+1$

$-x=-1\:|\times(-1)$

$x=1$

$III)-(x-1)=-(2x-2)$

$-x+1=-2x+2$

$-x+2x=2-1$

$-x=1\:|\times(-1)$

$x=-1$

$IV)-(x-1)=2x-2$

$-x+1=2x-2$

$-x-2x=-2-1$

$-3x=-3 \:|\div(-3)$

$x=1$