=2⁷ - 7²⁰²² 

=2⁷ - 7²⁰²² 

Dễ mà

Bn quy đồng mẫu chung là(3+x)×(3-x)

1152-(374+1152)+(374-65)

=1152-374-1152+374-65(theo quy tắc đổi dấu)

=(1152-1152)+(-374+374)-65

=0+0-65

=-65

1152-374-1152+374-65 =(1152-1152) +(-374+374)-65=0+0-65= 0-65= -65

1152-[374+1152]+[374-65]=[374+(1152-1152)]+(374-65)=374+(374-65)=683

372,463 x 999 + 372,463

=372,463 x (999+1)

=372,463 x 1000

=372463

 372,463x999+372,463

=372,463x(999+1)

=372,463x1000

=372463

372,463 x 999 + 372,463

= 372,463 x 999 + 372,463 x 1

= 372,463 x ( 999 + 1 )

= 372,463 x 1000

= 372463

a: \(=-\left(10x^2+15x-8x-12\right)=-10x^2-7x+12\)

-10x^2-7x+12

= 12-7x-10x^2

\(3^2\cdot5+2^3\cdot10-3^4:3\\ =9\cdot5+8\cdot10-3^4\\ =45+80-27\\ =98\)

\(3^2.5+2^3.10-3^4:3\)

\(=9.5+8.10-3^3\)

\(=45+80-27\)

\(=125-27\)

\(=98\)

\(#WendyDang\)

Anh ơi, dòng 2 ( \(3^4:3\) thì ra \(3^3\) -> a mới đổi thành được \(27\) chứ ạ? )

a, (y-476)x2=2196x3
(y-476)x2=2196x2+2196
(y-476)x2-2196x2=2196
(y-476-2196)x2=2196
(y-(476+2196)x2=2196
(y-2672)x2=2196
(y-2672)x2=1098x2
(y-2672)x2-1098x2=0
(y-2672-1098)x2=0
(y-(2672+1098)x2=0
(y-3770)x2=0
y-3770=0
y=3770
ĐS: y=3770

\(60-\left[15.2+\left(4+1^{35}\right)^2\right]\)
\(\Rightarrow60-\left[30+\left(4+1\right)^2\right]\)
\(\Rightarrow60-\left[30+25\right]\)
\(\Rightarrow60-55\)
\(\Rightarrow5\)

60-[30+(4+1)²

60-[30+25]

60-55

5

Ta có:

\(\left(x-1\right).\left(x+1\right).\left(x+2\right)\)

\(=\left(x^2+x-x-1\right).\left(x+2\right)\)

\(=\left(x^2-1\right).\left(x+2\right)\)

\(=x^3+2x^2-x-2\)