\(71\cdot64+32\cdot\left(-7\right)-13\cdot32\)

\(=32\cdot2\cdot71+32\cdot\left(-7\right)+32\cdot\left(-13\right)\)

\(=32\left(142-7-13\right)\)

\(=32\cdot122=3904\)

Lời giải:
a.

$21\times 23-3\times 7\times (-17)$

$=21\times 23-21\times (-17)$

$=21\times 23+21\times 17=21\times (23+17)=21\times 40$

$=840$

b.

$42\times 3-7\times [(-34)+18]$

$=7\times 18-7\times (-16)$

$=7\times 18+7\times 16=7\times (18+16)=7\times 34=238$

c.

$=142\times 32+32\times (-7)-13\times 32$

$=32\times (142-7-32)=32\times 103=3296$

d.

$=13\times [(23-17)-(23+17)]$

$=13\times (23-17-23-17)=13\times (-34)=-442$

( - 28 ) x ( -32 ) + 32 x ( 100 - 28 )

= 28 x 32 + 32 x 100 - 32 x 28

= 32 x ( 28 + 100 - 28 )

= 32 x 100

= 3200

(-28).(-32+32).(100-28)

=(-28).(-32)+32.100-28

=[(-28)-28].[(-32)+32].100

=(-56).0.100

=0

32x+9+7=11

<=> 32x=11-9-7=-5

<=> x=-5/32

32x + 9 + 7 = 11

32x = 11 - 9 - 7

32x = -5

=> x = -5/32

3232

-7548

-4851

-65

Tích cho mk nha

a, -32 . (-101) = 32 . 101 = 32 . (100+1) = 32 . 100 + 32 = 3232

b,102 . (-74)= -74 . (100+2)= -7400 - 148 = -7548

c,-49 . 99 = -49 .( 100 - 1 ) = -4900 + 49 = -4851 

d, 45 - 5.( 9+13 ) = 45 - 5.22= 45 - 110 = -65

a,16 X 50X-25X(-250)

=(16 X-25)X50X(-250)

=-400X50X-250

=-20000X-250

=5000000

b,-54X76+12X(-76)

=76X(-54-12)

=76X(-66)

=-5016

c,32X(-64)-64X68

=-64X(32+68)

=-64X100

=-6400

d,19X42.(-19)+38X5

=19X(42-1)+19X2X5

=19X41+19X10

=19X(41+10)

=19X51=969

a) 16.50.(-25).(-250)

=[16.(-25)].50.(-250)

=-400.50.(-250) 

=-20000.(-250) 

=5000000

b,-54.76+12.(-76)

=76.(-54-12)

=76.(-66)

=-5016

c,32.(-64)-64.68

=-64.(32+68)

=-64.100

=-6400

d,19.42.(-19)+38.5

=19.(42-1)+19.2.5

=19.(42-1)+19.(2.5)

=19.41+19.10

=19.(41+10)

=19.51

=969 

Lời giải:
$3^{2x}=27.3^x$

$\Rightarrow 3^{2x}=3^3.3^x=3^{3+x}$

$\Rightarrow 2x=3+x$

$\Rightarrow x=3$

3^2x+6=9¹⁰=3²⁰

=>2x+6=20

=>2x=20-6=14

=>x=14:2=7.

3^2x+6=9¹⁰

⇒ 3^2x+6=(3²)¹⁰

⇒ 3^2x+6=3^2.10

⇒ 3^2x+6=3²⁰

⇒ 2x+6=20

⇒ 2x= 20-6=14

⇒ x=14:2=7