\(\frac{58x63}{42x87}=\frac{2x29x7x9}{6x7x3x29}=\frac{2x7x9x29}{2x7x3x3x29}=1\)

\(\frac{58\times63}{42\times87}=\frac{29\times2\times7\times9}{6\times7\times29\times3}\)

                   \(=\frac{29\times2\times7\times3\times3}{3\times2\times7\times29\times3}\)

                      \(=1\)

bạn chỉ cần gạch các số giống nhau là ra đáp án

58 x 63 : 42 : 87 = 1 nhé bạn

58*63/42/87=1 

k cho mình nhé

X=(1800+600):30):560:(315:35)

X=(2400:30):560:9

X=80:560:9

X=80x1/560x1/9

X=1/7x1/9

X=1/63

A=58x72+63x81-58x52-63x61

  = (58x72-58x52)+(63x81-63x61)

  = 58(72-52)+63(81-61)

  = 58x20+63x20

  = 1160+1260

  = 2420

a) Ta có: \(\left(-65\right)\cdot\left(87-17\right)-87\cdot\left(17-65\right)\)

\(=-65\cdot87+65\cdot17-87\cdot17+87\cdot65\)

\(=17\left(65-87\right)=17\cdot\left(-22\right)=-374\)

b) Ta có: \(\left(135-35\right)\cdot\left(-37\right)+37\cdot\left(-42-58\right)\)

\(=\left(-100\right)\cdot37+37\cdot\left(-100\right)\)

\(=37\left(-100-100\right)=37\cdot\left(-200\right)=-7400\)

Carm ơn bạn nhiều ạ!

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

=142x42+142x58

=142x(42+58)

=142x100

=14200

\(\left(100+42\right)\times42+\left(200-58\right)\times58\)

\(=142\times42+142\times58\)

\(=142\times\left(42+58\right)\)

\(=142\times100=14200\)

0,17 x 250 + 63 x 1,7 - 87 x 1,7

=1,7x25+ 63 x 1,7 - 87 x 1,7

=1,7x(25+63-87)

=1,7x1

=1,7

\(0,17\times250+63\times1,7-87\times1,7\)
\(=0,17\times10\times25+63\times1,7-87\times1,7\)
\(=1,7\times25+63\times1,7-87\times1,7\)
\(=1,7\times\left(25+63-87\right)\)
\(=1,7\times1\)
\(=1,7\)

12,7 + 12,7 + 12,7 + 12,7 x 8 - 12,7

= 12,7 x (1 + 1 + 1 + 8 - 1)

= 12,7 x 10

= 127

(100 + 42) x 42 + (200 - 58) x 58

= 142 x 42 + 142 x 58 

= 142 x (42 x 58)

= 142 x 100

= 14200

(100 + 42 ) x 42 + ( 200 - 58 ) x 58 

= 142 x 42 + 142 x 58

= 142 x ( 42 + 58 )

= 142 x 100

= 14200

( 100 + 42 ) x 42 + ( 200 - 58 ) x 58

= 142 x 42 + 142 x 58

= 142 x ( 42 + 58 )

= 142 x 100

= 14200

a) X : 4 = 58                                                     b) 7 x X = 63

         X = 58 x 4                                                         X = 63 : 7

          X = 232                                                            X = 9