(2x² + 1)(x-3)=0

\(\Rightarrow\orbr{\begin{cases}2x^2+1=0\\x-3=0\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}2x^2=-1\Rightarrow x^2=-\frac{1}{2}\left(vl\right)\\x=3\end{cases}}\)

Vậy x=3

48-(15-x)⁵=48

     (15-x)⁵=48-48

     (15-x)⁵=0

=>  15-x   =0

           x    =15-0

           x    =15

Vậy x=15

x 4 2 = x 12 x 5 ( x ≠ 0 )

⇒ x8 = x7.

⇒ x8 − x7 = 0

⇒ x7.(x − 1) = 0

⇒ x – 1 = 0 (vì x7 ≠ 0)

⇒ x = 1

Vậy x = 1.

ngu như con lợn lò

5x7x77-7x60+49x25-15x42=2870

thằng hâm

180360180

\(13\cdot42\cdot33\cdot26\cdot35\)

\(=\left(42\cdot35\right)\cdot\left(13\cdot26\right)\cdot33\)

\(=1470\cdot338\cdot33\)

\(=16396380\)

\(1234 + 678 + 766 + 1322=(1234+766)+(678+1322)=2000+2000=4000\)

\(427\times42+427\times35+427\times23=427\times\left(42+35+23\right)=427\times100=42700\)

\(248\times125-248\times24-248=248\times\left(125-24-1\right)=248\times100=24800\)

chu so tận cùng la 6

 vvhdxfhysrwy

chữ số tận cùng là 6

a.

\(\left(100+42\right)\times42+\left(200-58\right)\times58=142\times42+142\times58=142\times\left(42+58\right)=142\times100=14200\)

b.

\(\left(1998\div18-1443\div13\right)\times\left(16996-1110\div30\times305\right)=\left(111-111\right)\times\left(16996-1110\div30\times305\right)\)

\(=0\times\left(16996-1110\div30\times305\right)=0\)

c.

\(5^3_5+1,75+6^1_8+4^1_4+3,875+3,4=5,6+1,75+6,125+4,25+3,875+3,4\)

\(=\left(5,6+3,4\right)+\left(1,75+4,25\right)+\left(6,125+3,875\right)=9+6+10=25\)

Giải theo cách lớp 5

a)(100+42)x42+(200-58)x58

=142x42-142x58

=(42-58)x142

=(-16).142

=-2272

b)(1998:18-1443:13)x(16996-1110:30x305)

=(111-111)x(16996-1110:30x305)

=0x(16996-1110:30x305)

=0

c)\(5\frac{3}{5}\)+1,75+\(6\frac{1}{8}\)+\(4\frac{1}{4}\)+3,875+3,4

=(1,75+\(4\frac{1}{4}\))+(3,875+\(6\frac{1}{8}\))+(3,4+\(5\frac{3}{5}\))

=6+10+9

=25

b,bang11000 

11000

a, 2 x 31 x 12 + 4 x 6 x 42 + 8 x 27 x 3