a: =10000+1025=11025

b: =15x(2+3+5)=150

\(a,\left(3416+6584\right)+1025=11025\\ b,15\times\left(2+3+5\right)=150\)

a)

 3416 +1025 + 6584 =( 3416+6584)+1025

                                = 10000+1025

                                =11025

b) 15 x 2 + 15 x 3 + 15 x 5 = 15.(2+3+5)

                                            =   15. 10

                                         =150

\(a,3416+1025+6584\\ =\left(3416+6584\right)+1025\\ =10000+1025\\ =11025\\ b,15\times2+15\times3+15\times5\\ =15\times\left(2+3+5\right)\\ =15\times10\\ =150\)

a,3416+1025+6584=(3416+6584)+1025=10000+1025=11025b,15×2+15×3+15×5=15×(2+3+5)=15×10=150

a)3416+1025+6584

=(3416+6584)+1025

=10 000+1025

=11 025

\(a,21.\left(-15\right)+67.\left(-15\right)+\left(-15\right)+\left(-15\right).12\)

\(=21.\left(-15\right)+67.\left(-15\right)+\left(-15\right).1+\left(-15\right).12\)

\(=-15.\left(21+67+1+12\right)\)\(=-15.101=-1515\)

\(b,\left(-30\right)+76+30\)\(=\left(-30+30\right)+76=0+76=76\)

\(d,15.\left\{22-\left[400:\left(140+12.5\right)\right]\right\}\)

\(=15.\left\{22-\left[400:\left(140+60\right)\right]\right\}\)

\(=15.\left[22-\left(400:200\right)\right]\)

\(=15.\left(22-2\right)=15.20=600\)

a. (-15) x 101 = -1515 

b. (-30+30) +76 = 76

a) 21.(-15)+67.(-15)+(-15)+(-15).12

= (-15).(21+67+1+12)

= (-15).101

= -1515

b) (-30)+76+30

= [(-30)+30]+76

= 0+76 = 76

c) 15.{22-[400:(140+12.5)]}

= 15.{22-[400:(140+60)]}

= 15.{22-[400:200]}

= 15.{22-2}

= 15.20

= 300

a)1/5:15/2*6/7+1/21=777/11025

b) 1/15*2/3+2/4=170/180

 nhớ

k hiểu

a=37/525

b=49/90

a)

Ta có : ( 1 + 2 + 3 + ... + 99)

Số số hạng là:       ( 99 - 1 )  : 1 + 1 = 100

Tổng là:                 ( 99 + 1 ) x 100 : 2 = 5000

=> 5000 x ( 13  - 12 - 1 ) x 15

=> 5000 x 10 x 15

=> 50000 x 15

=> 750000

Ko muốn vt nx :))

bt làm r

a. (83+234)-(34-17)

= (243-34)-(83+17)

= 200-100

= 100

B.(-15)+13+15.(36-25)

= (-15)+15.13+11

= 13+11

= 24