a)=1300

b)=8600

a ) \(=1300\)

b ) \(=8600\)

86.153 − 530.8,6 = 86.153 – 53.10.8,6

= 86.153 − 53.86 = 86.(153 − 53) = 86.100=8600

a, \(97.13+130.13\)

\(=13\left(97+130\right)\)

\(=13.227\)

\(=2951\)

b, \(86.153-530.8,6\)

\(=86.153-53.10.8,6\)

\(=86.153-53.86\)

\(=86\left(153-53\right)\)

\(=86.100\)

\(=8600\)

trả lời:

a) 97.13 + 130.13

= 13.( 97 + 130 )

= 13. 227

= 2951

b) 86.153 - 530.8,6

= 86.153 - 53.10.8,6

=86. 153 - 53.86

= 86. ( 153 - 53 )

= 86.100

= 8600

học tốt!

a) 97.13 + 130.0,3

= 97.13 + 13.3

= 13. ( 97 + 3 )

= 13.100

=1300

b) 86.153 - 530.8,6

= 86.153 - 53.86

= 86. ( 153 - 53 )

= 86. 100

= 8600

( Toán lớp 8 đây hả ???)

~HT~

a) \(97\cdot13+130\cdot0,3=97\cdot13+13\cdot10\cdot0,3=13\cdot\left(97+10\cdot0,3\right)=13\cdot100=1300\)

b)\(86\cdot153-530\cdot8,6=8,6\cdot10\cdot153-53\cdot10\cdot8,6=10\cdot8,6\cdot\left(153-53\right)=10\cdot8,6\cdot100=8600\)

bạn làm đc câu này ko: 

Bài 9: Tính nhanh

 a) 25² – 15²            b) 87² + 73²– 27²– 13²

đây có lẽ là toán lớp 5

a)97*13+130*0,3

=97*13+13*10*0,3

=97*13+13*3

=13*(97+3)

=13*100

=1300

b)86*153-530*8,6

=86*153-53*10*8,6

=86*153-53*86

=86*(153-53)

=86*100

=8600

a) \(97.13+130.0,3\\ =97.13+13.3\\ =13.\left(97+3\right)\\ =13.100=1300\)

b) \(86.153-530.8,6\\ =8,6.1530-530.8,6\\ =8,6.\left(1530-530\right)\\ =8,6.1000\\ =8600\)

Gì dài z má =))

\(x+x:0,25+x.2+x:0,125=0,45\)

\(\Leftrightarrow x+x:\dfrac{1}{4}+x.2+x:\dfrac{1}{8}=0,45\)

\(\Leftrightarrow x+x.4+x.2+x.8=0,45\)

\(\Leftrightarrow x\left(1+4+2+8\right)=0,45\)

\(\Leftrightarrow x.15=0,45\)

\(\Leftrightarrow x=0,03\)

X + X : 0.25 + X x 2 + X : 0.125 = 0.45

X + X x 4 + X x 2 + X x 8 =  0.45

X x (1+4+2+8)= 0.45

X x 15 = 0.45

X= 0.45 : 15

X= 0.03

X x1+X x4+X x2 +X x8 =0,45

=X x (1+4+2+8)=0,45

= X x15=0,45

=X =0,45 : 15

=X =0.03