180:{300:[450-(4x5^3-2^2x25)]}
180:{300:[450-(4x53-22x25)]}
180:{300:[450-(4.5^3-2^2.25)]}
\(180:\left\{300:\left[450-\left(4.5^3-2^2.25\right)\right]\right\}\\ =180:\left\{300:\left[450-\left(4.125-4.25\right)\right]\right\}\\ =180:\left\{300:\left[450-\left(500-100\right)\right]\right\}\\ =180:\left\{300:\left[450-400\right]\right\}\\ =180:\left\{300:50\right\}\\ =180:6\\ =30\)
\(180:\left\{300:\left[450-\left(4.5^3-2^2.25\right)\right]\right\}\\ =180:\left\{300:\left[450-\left(4.125-4.25\right)\right]\right\}\\ =180:\left\{300:\left[450-\left(4.100\right)\right]\right\}\\ =180:\left\{300:\left[450-400\right]\right\}\\ =180:\left\{300:50\right\}\\ =180:6\\ =30\)
Chứng minh rằng E=90+180+300+450 chia hết cho 15.
Câu 1 Thực hiện phép tính
a) 3^3 +3^2 - (2^7 : 2^5 + 7^8 : 7^7)
b) 27.77 + 27.27 - 27
c) 52 : (43-30) + 144 - 16
d) 174 : {2[36 + (4^2 - 23)]}
e) 180 : {300 : [450 - (4.5^3 - 2^2.25)]}
f) 3^2.101 - 3^2.101^0
( Dấu "^" là dấu mũ nha )
\(a,3^3+3^2-\left(2^7:2^5+7^8:7^7\right)=27+9-\left(2^2+7\right)=36-11=25\)
\(b,27.77+27.27-27=27\left(77+27-1\right)=27.103=2781\)
\(c,52:\left(43-30\right)+144-16=52:13+128=4+128=132\)
\(f,3^2.101-3^2.101^0=3^2\left(101-101^0\right)=9\left(101-1\right)=9.100=900\)
a.=27+9-(2^2+7^1) =36-(4+7) =36-11 =25
33+32-(27:25+78:77)
=27+9-(22+7)
=36-(4+7)
=36-11
=25
b.bạn tự lm nha
c.52:(43-30)+144-16
=52:13+144-16
=4+144-16
=148-16
=132
d.174:{2[36+(42-23)]}
=174:{2[36+(16-23)]}
=174:{2[36+-7]}
=174:{2.29}
=174:58
=3
x+300=450+450
x + 300 = 450 + 450
x + 300 = 900
x = 900 - 300
x = 600
Tính giá trị của các biểu thức
a) 450 – ( 25 – 10) = ..........................
= ..........................
450 – 25 – 10 = ..........................
= ..........................
b) 180 : 6 : 2 = ..........................
= ..........................
180 : ( 6 : 2 ) = ..........................
= ..........................
c) 410 – (50 +30) = ..........................
= ..........................
410 - 50 + 30 = ..........................
= ..........................
d) 16 x (6 : 3) = ..........................
= ..........................
16 x 6 : 3 = ..........................
= ..........................
a) 450 – ( 25 – 10) = 450 – 15
= 435
450 – 25 – 10 = 425 – 10
= 415
b) 180 : 6 : 2 = 30 : 6
= 15
180 : ( 6 : 2 ) = 180 : 3
= 60
c) 410 – (50 +30) = 410 -80
= 330
410 - 50 + 30 = 360 + 30
= 390
d) 16 x (6 : 3) = 16 x 2
= 32
16 x 6 : 3 = 96 : 3
= 32
Câu 1: Tìm x biết :
a, 245-12.8+18:3
b, 23.65+23.35-360
c, 33+32-(27:25+78:77)
d, 180:{300:[450-(4.53-22.25)]}
\(a,245-96+6\)
\(=155\)
\(b,=23\times\left(65+35\right)\)- 360
\(=23\times100-360\)
\(=1940\)
\(c,3^3+3^2-\left(2^2+7\right)\)
\(3^3+3^2-\left(4+7\right)\)
=\(3^3+3^2-11\)
=\(27+9-11\)
a,245 - 12.8 + 18:3
=155
b,23.65+23.35-360
=23.(65+35) -360
=2300 - 360=1940
c,33+32-(27:25+78:77)
=33+32
Tính M bằng cách nhanh nhất: M = 3/1x4 + 3/4x7 + 3/7x10 + .... + 3/19x22 + 3/22x25
Lời giải:
$M=\frac{4-1}{1\times 4}+\frac{7-4}{4\times 7}+\frac{10-7}{7\times 10}+....+\frac{22-19}{19\times 22}+\frac{25-22}{22\times 25}$
$=1-\frac{1}{4}+\frac{1}{4}-\frac{1}{7}+\frac{1}{7}-\frac{1}{10}+....+\frac{1}{22}-\frac{1}{25}$
$=1-\frac{1}{25}=\frac{24}{25}$
x + 450 = 600 + 180
x+450=600+180
x+450=780
x=780-450
x=330
x + 450 = 600 + 180
x + 450 = 780
x = 780 - 450
x = 330