64x52+37x52-2,26

= 52x(64+37)-2,26

= 52x   101-2,26

=      5252-2,26

=5249,74

Cảm ơn bn

130 - 3x = 88

         3x = 130 - 88

         3x = 42

           x = 42 : 3

           x = 14

2xX+X:0,125=10

2xX+Xx1/8=10

Xx(2+1/8)=10

Xx2,125=10

X=10:2,125

X=80/17

x:0,125=10-2xX

X        =1,25-0,25xX

x+0,25xX=1,25

x            =1

có đúng không?

\(a)\) \(2x-5=21\)

\(\Leftrightarrow\) \(2x=21+5\)

\(\Leftrightarrow\) \(2x=26\)

\(\Leftrightarrow\) \(x=26:2\)

\(\Leftrightarrow\) \(=13\)

\(b)\) \(\frac{3}{4}+\frac{1}{4}x=\frac{5}{6}\)

\(\Leftrightarrow\) \(\frac{1}{4}x=\frac{5}{6}-\frac{3}{4}\)

\(\Leftrightarrow\) \(\frac{1}{4}x=\frac{1}{12}\)

\(\Leftrightarrow\) \(x=\frac{1}{3}\)

ủ cái này sao đc

(12 + 77 + 34 + 23 + 88 + 45 + 55 + 66) x (45200 – 1808 x 25)

=(12 + 77 + 34 + 23 + 88 + 45 + 55 + 66) x (45200-45200)

=(12 + 77 + 34 + 23 + 88 + 45 + 55 + 66) x 0

=0

(12 + 77 + 34 + 23 + 88 + 45 + 55 + 66) x (45200 – 1808 x 25)

= (12 + 77 + 34 + 23 + 88 + 45 + 55 + 66) x (45200 – 45200 )

= (12 + 77 + 34 + 23 + 88 + 45 + 55 + 66) x 0

= 0 

(45+75)*66+(75+45)*34

=(45+75)*(66+34)

=120*100

=12000

11+22+33+44+55+66+77+88+99:11

=11+22+33+44+55+66+77+88+9

=(11+9)+(22+88)+(33+77)+(44+66)+55

=20+110*3+55

=20+330+55

=405

Ta có :

a, (45 + 75) x 66 + (75 + 45) x 34

=  (45 + 75) x (66 + 34)

=   120  x 100

=  12000

11 + 22 + 33 + 44 + 55 + 66 + 77 + 88 + 99 : 11

= 33 + 77 + 121 + 165 + 9

= 405