Dạng 2. Tìm x

$x+5=8$

$x=8-5$

$x=3$

$a){5.2}^2+\left(x+3\right)=5^2$

$x+3=5^2-{5.2}^2$

$x+3=5.\left(5-4\right)$

$x+3=5$

$x=2$

$b)2^3+\left(x–3^2\right)=5^3-4^3$

$x-3^2=125-64-8$

$x-9=53$

$x=62$

$c)4\left(x–5\right)–2^3=2^4.3$

$4(x-5)=2^4.3+2^3$

$4(x-5)=2^3(6+1)$

$4(x-5)=2^3.7$

$x-5=2^3.7:4$

$x-5=14$

$x=19$

$d)5\left(x+7\right)–10=2^3.5$

$5\left(x+7\right)=2^3.5+10$

$5(x+7)=2.5(2^2+1)$

$x+7=2.5$

$x=3$

$e)7^2–7\left(13–x\right)=14$

$7.\left[7-\left(13-x\right)\right]=14$

$7-\left(13-x\right)=2$

$13-x=7-2$

$13-x=5$

x=8

$f)5x–5^2=10$

$5x=10+25$

$5x=3$

$x=7$

$g)9x–{2.3}^2=3^4$

$9x-{2.3}^2=3^4$

$9x=3^4+{2.3}^2$

$9x=3^2\left(3^2+2\right)$

$x=11$

$h)10x+2^2.5={10}^2$

$10x=2^2{.5}^2-2^2.5$

$10x=2.5\left(2.5-2\right)$

$x=8$

$i)125–5\left(4+x\right)=15$

$5\left(4+x\right)=125-15$

$5\left(4+x\right)=110$

$4+x=110:5$

$4+x=22$

$x=18$

$j)2^6+\left(5+x\right)=3^4$

$5+x=81-64$

$5+x=17$

$x=12$

$a)15:\left(x+2\right)=3$

$x+2=15:3$

$x+2=5$

$x=5-2$

$x=3$

$b)20:\left(x+1\right)=2$

$1+x=20:2$

$1+x=10$

$x=10-1$

$x=9$

$c)240:\left(x-5\right)=2^2{.5}^2-20$

$240:\left(x-5\right)=100-20$

$240:\left(x-5\right)=80$

$x-5=240:80$

$x-5=3$

$x=8$

$3(x+1)=96-42$

$3(x+1)=54$

$x+1=54:3$

$x+1=18$

$x=17$

$e)5\left(x+35\right)=515$

$x+35=515:5$

$x+35=103$

$x=103-35$

$x=68$

$f)12x-33=3^2{.3}^3$

$12x=243+33$

$12x=276$

$x=23$

$g)541-\left(218+x\right)=73$

$218+x=541-73$

$218+x=468$

$x=468-218$

$x=250$

$h)1230:3\left(x-20\right)=10$

$3(x-20)=1230:10$

$3(x-20)=123$

$x-20=41$

$x=41+20$

$x=61$

$a)48-3\left(x+5\right)=24$

$3(x+5)=48-24$

$3(x+5)=24$

$x+5=24:3$

$x+5=8$

$x=8-5$

$x=3$

$b)2^{x+1}-2^x=32$

$2^x.2-2^x=2^5$

$2^x=2^5$

$x=5$

$c)\left(15+x\right):3=3^{15}:3^{12}$

$\left(15+x\right):3=3^3$

$15+x=27.3$

$15+x=81$

$x=81-15$

$x=66$

$d)250-10\left(24-3x\right):15=244$

$4x+9=13$

$4x=13-9$

$4x=4$

$x=1$

$2x-1=3^2$

$2x=9+1$

$2x=10$

$x=5$

$5^{x-1}=5^{25}:5^{25}$

$5^{x-1}=1$

$5^{x-1}=5^0$

$x-1=0$

$x=1$

$h)x-48:16=37$

$x-3=37$

$x=37+3$

$x=40$

$a)\left[\left(8x-12\right):4\right]{.3}^3=3^6$

$\left[\left(8x-12\right):4\right]=3^6:3^3$

$\left(8x-12\right):4=3^3$

$8x-12=27.4$

$8x-12=108$

$8x=120$

$x=15$

$b)41-2^{x+1}=9$

$2^{x+1}=41-9$

$2^{x+1}=32$

$2^{x+1}=2^5$

$x+1=5$

$x=4$

$c)3^{2x-4}-x^0=8$

$3^{2x-4}-1=8$

$3^{2x-4}=9$

$3^{2x-4}=3^2$

$2x-4=2$

$2x=6$

$x=3$

$d)65-4^{x+2}={2014}^0$

$4^{x+2}=65-1$

$4^{x+2}=64$

$4^{x+2}=4^3$

$x+2=3$

$x=1$

$e)120+2.\left(8x-17\right)=214$

$2(8x-17)=214-120$

$2(8x-17)=94$

$8x-17=47$

$8x=64$

$x=8$

$f)5^{2x–3}–{2.5}^2=5^2.3$

$5^{2x-3}=5^2.3+{2.5}^2$

$5^{2x-3}=5^3$

$2x-3=3$

$2x=6$

$x=3$

$g)30-\left[4\left(x-2\right)+15\right]=3$

$4\left(x-2\right)+15=30-3$

$4\left(x-2\right)+15=27$

$4\left(x-2\right)=27-15$

$4\left(x-2\right)=12$

$x-2=3$

$x=5$

$h)740:\left(x+10\right)={10}^2–2.13$

$740:\left(x+10\right)=100-26$

$740:\left(x+10\right)=74$

$x+10=740:74$

$x+10=10$

$x=0$

$\left(19x+{2.5}^2\right):14={\left(13-8\right)}^2-4^2$

$\left(19x+{2.5}^2\right):14=5^2-4^2$

$\left(19x+{2.5}^2\right):14=9$

$19x+{2.5}^2=14.9$

$19x+50=126$

$19x=126-50$

$19x=76$

$x=4$

${2.3}^x={10.3}^{12}+{8.27}^4$

${2.3}^x={10.3}^{12}+8.{\left(3^3\right)}^4$

${2.3}^x={10.3}^{12}+{8.3}^{12}$

${2.3}^x={18.3}^{12}$

$3^x={9.3}^{12}$

$3^x=3^2{.3}^{12}$

$3^x=3^{14}$

$x=14$

${2.3}^{x+1}-3^x=135$

${2.3}^x.3-3^x=135$

$3^x.5=135$

$3^x=27$

$3^x=3^3$

$x=3$

$15:\left(x+2\right)=\left(3^3+3\right):10$

$15:\left(x+2\right)=30:10$

$15:\left(x+2\right)=3$

$x+2=15:3$

$x+2=5$

$x=3$

$4.{\left(3x-1\right)}^3-5^2=475$

$4.{\left(3x-1\right)}^3=475+25$

$4.{\left(3x-1\right)}^3=500$

${\left(3x-1\right)}^3=125$

${\left(3x-1\right)}^3=5^3$

$3x-1=5$

$x=2$

$2^x+2^{x+1}=96;$

$2^x+2^x.2=96$

$2^x.3=96$

$2^x=32$

$2^x=2^5$

$x=5$

$3^{8x+4}={81}^{x+3}$

$3^{4(2x+1)}={81}^{x+3}$

${81}^{2x+1}={81}^{x+3}$

$2x+1=x+3$

$x=2$

$x^{2015}=x^{2016}$

$x^{2015}=x^{2015}.x$

$x^{2015}.x-x^{2015}=0$

$x^{2015}\left(x-1\right)=0$

$\left[\begin{array}{l}{x}^{2015}=0\\ x-1=0\end{array}\right.\Rightarrow \left[\begin{array}{l}x=0\\ x=1\end{array}\right.$

Vậy x = 0 hoặc x = 1

${\left(4x-1\right)}^3=27.125$

${\left(4x-1\right)}^3=3^3{.5}^3$

${\left(4x-1\right)}^3={15}^3$

$4x-1=15$

$4x=16$

$x=4$