a) \(250 + 250 × 2 = 250 + 500 = 750 \\ (250 + 250) × 2 = 500 × 2 = 1 000\)

b)\( 750 – 50 × 5 = 750 – 250 = 500\\ (750 – 50) × 5 = 700 × 5 = 3 500\)
c) \(210 × 4 – 4 × 210 = 840 – 840 = 0\\ 3 × (270 : 9) × 0 = 0\)

 250 x 15 + 250 x 50 + 250 x 35.

= 250 x ( 15 + 50 + 35 ).

= 250 x 100

= 25000.

k mik nha!!

#Học tốt.

\(250\times15+250\times50+250\times35\)

\(=250\times\left(15+50+35\right)\)

\(=250\times100\)

\(=25000\)

 #hoktot<3#

Ta có:

      \(250\times15+250\times50+250\times35\)

\(=250\times\left(15+50+35\right)\)

\(=250\times100\)

\(=25000\)

x=250-50

x=200

x + 50 = 250

x         = 250 - 50

x         = 200

x+50=250

x=250-50

x=200

x+50=610

x=610-50

x=560

x + 50 = 250 + 360

x + 50 = 610

x        = 610 - 50

x        = 560

x + 50 = 250 + 360

x + 50 = 610

x = 610 - 50

x = 560

x +90 = 250 -50

x + 90 = 200

x = 200 - 90 

x = 110

x + 90 = 250 - 50

x + 90 = 200

x        = 200 - 90

x        = 110

x+90=250-50

x+90=200

     x=200-90

      x=110

Vậy x=110

\(300-5\times Y+50=250\)

\(5\times Y+50=50\)

\(5\times Y=0\)

\(Y=0\)

Ta có : 300 - 5y + 50 = 250

\(\Leftrightarrow\)350 - 5y = 250

\(\Leftrightarrow\)5y = 350 - 250

\(\Leftrightarrow\)5y = 100

\(\Rightarrow\)y     = 20

Vậy : y = 20

300-5y+50=250

lay 250-50=200 roi lay 300-200=100

lay 100chia cho5 thi se tim ra y

vay y =20

=(250-50)- (0,95x40)x(10x0,1)x(0,125x80)
=200 - (38 x1x10)
=200-380
=-180 
 

99570

99,570

98

bấm máy tính cũng được mà.

giải chi tiết nha

\(100-100:\left[0,4\times250-\left(100-50\%\times50\right)+25\right]\)

\(=100-100:\left[100-\left(100-25\right)+25\right]\)

\(=100-100:25=100-4=96\)

(250 x 45 x90) : (50 x 15 x 30)

=[(250.90).45]:[(50.30).15]

=[22500.45]:[150.15]

=1012500:2250

=450

  (250 x 45 x 90) : (50 x 15 x 30)

=[(50 x 5) x ( 15x3) x ( 30x3)] : (50 x 15 x 30)

=[(50 x 15 x 30) x (5 x 3 x 3)] : (50 x 15 x30)

=5 x 3 x 3=45