x x 90 = 900
x x 900 = 0,100 x 90
x x 900 = 0 .100 x 90
x x 900 = 9
x = 9 : 900
x = 0.01
x x 900 = 0,1 x 90
x x 900 = 9
x = 9 : 900
x = 0,01
nha
x + 90 + 10 = 900
x+(90+10) = 900
x+100 = 900
x = 900-100
x = 800
x + 90 + 10 = 900
x + 90 = 900 - 10
x + 90 = 890
x = 890 - 90
x = 800
x+90+10=900
x+90=900-10
x+90=880
x=800-90
x=710
x + 300 = 200
x - 400 = 900
X x 90 = 180
240 : x = 60
X= 200 - 300 = -100
X= 900 + 400 = 1300
X= 180 : 90 = 2
X= 240 : 60 = 4
Tìm x :
x + 300 = 200
x = 200 - 300
x = -100
x - 400 = 900
x = 900 + 400
x = 1300
X x 90 = 180
X = 180 : 90
X = 2
240 : x = 60
x = 240 : 60
x = 4
\(x+300=200\)
\(\Rightarrow x=200-300\Rightarrow x=-100\)
\(x-400=900\Rightarrow x=900-400=500\)
\(xX90=180\Rightarrow x=180:90=9\)\(;\)\(240:x=60\Rightarrow x=240:60=4\)
(1000 x 0,5-900 x 0,5-90 x 0,5) - (120 x 0,25 + 240 x 0,5)=?
Tìm a:
a + 90 = 190 - 20
a x 10 = 900
\(a+90=190-20\)
\(\Leftrightarrow a+90=170\)
\(\Leftrightarrow a=170-90\)
\(\Leftrightarrow a=80\)
\(a\times10=900\)
\(\Leftrightarrow a=900\div10\)
\(\Leftrightarrow a=90\)
a + 90 = 190 - 20
<=> a + 90 = 170
a = 170 - 90
a = 80
_______________
a x 10 = 900
a = 900 : 10
a = 90
\(a+90=170\)
\(a=170-90\)
\(a=80\)
\(a=900:10=90\)
9 x 1 + 90 x 2 + 900 x 3 + 851 x 4
Tính giúp mình nha k 10 bạn nhanh nhất
9 x 1 + 90 x 2 + 900 x 3 + 851 x 4
= 9 + 180 + 2700 + 3404
= 189 + 2700 + 3404
= 2889 + 3404
= 6293
9 x 1 + 90 x 2 + 900 x 3 + 851 x 4
= 9 + 180 + 2700 + 3404
= 6293
Tính nhanh:
a. ( 48 x 0,75 - 240 : 10 ) - ( 16 x 0,5 - 16 : 4 )
b. (1000 x 0,1 - 900 x 0,1 - 90 x 0,1 ) x ( 142 x 0,5 - 240 x 0,25 )
a. ( 48 x 0,75 - 240 : 10 ) - ( 16 x 0,5 - 16 : 4 )
=(36-24)-(8-4)
=12-4
=8
b. (1000 x 0,1 - 900 x 0,1 - 90 x 0,1 ) x ( 142 x 0,5 - 240 x 0,25 )
=(100-90)x(71-60)
=10x11
=110
# mui #
a
= ( 24 + 12 ) - ( 9 - 4 )
= 36 - 5
= 31
Tính hợp lí
a) C = 75,284 x 15,137 x (9,5 - 4,75 x 2) + 231 x (7,25 + 2,75).
b) D = (1000 x 0,1 – 900 x 0,1 – 90 x 0,1)x(142 x 0,5 – 240 x 0,25).
c) E = 3,54 + 73 + 0,23 x 25 + 3,54 x 27 + 0,17 x 25 .
Tính hợp lí:
a) C = 75,284 x 15,137 x (9,5 - 4,75 x 2) + 231 x (7,25 + 2,75).
b) D = (1000 x 0,1 – 900 x 0,1 – 90 x 0,1)x(142 x 0,5 – 240 x 0,25).
c) E = 3,54 + 73 + 0,23 x 25 + 3,54 x 27 + 0,17 x 25
a) \(C=75,284\cdot15,137\cdot\left(9,5-4,75\cdot2\right)+231\left(7,25+2,75\right)\)
\(C=75,284\cdot15,137\cdot\left(9,5-9,5\right)+231\cdot10\)
\(C=75,284\cdot15,137\cdot0+2310=2310\)
b) \(D=\left(1000\cdot0,1-900\cdot0,1-90\cdot0,1\right)\left(142\cdot0,5-240\cdot0,25\right)\)
\(D=\left[0,1\left(1000-900-90\right)\right]\left(142\cdot0,5-240\cdot0,5\cdot\frac{1}{2}\right)\)
\(D=\left(0,1\cdot10\right)\left(142\cdot0,5-140\cdot0,5\right)\)
\(D=0,5\left(142-140\right)\)
\(D=\frac{1}{2}\cdot2=1\)
c) \(E=3,54+73+0,23\cdot25+3,54\cdot27+0,17\cdot25\)
\(E=3,54\left(1+27\right)+73+25\left(0,23+0,17\right)\)
\(E=3,54\cdot28+73+25\cdot0,4\)
\(E=99,12+73+10\)
\(E=99,12+1+72+10\)
\(E=100,12+72+10=182,12\)