189-2(93-3x)=21
378 + 2 = ?
189 + 93 = ?
\(378+2=380\)
\(189+93=282\)
hok tốt
Tính giá trị biểu thức (189 + 396) : 9 *
đúng hay sai
(189 + 396) : 9 = 189 : 9 + 396 = 21 + 396 = 417
(189 + 396) : 9 = 189 + 396 : 9 = 189 + 44 = 233
(189 + 396) : 9 = 189 : 9 + 396 : 9 = 21 + 44 = 65
Tính giá trị biểu thức (189 + 396) : 9 *
đúng hay sai
(189 + 396) : 9 = 189 : 9 + 396 = 21 + 396 = 417 S
(189 + 396) : 9 = 189 + 396 : 9 = 189 + 44 = 233 S
(189 + 396) : 9 = 189 : 9 + 396 : 9 = 21 + 44 = 65 Đ
S (189 + 396) : 9 = 189 : 9 + 396 = 21 + 396 = 417
S (189 + 396) : 9 = 189 + 396 : 9 = 189 + 44 = 233
Đ (189 + 396) : 9 = 189 : 9 + 396 : 9 = 21 + 44 = 65
Tìm x biết
a. 189-2.(93-x) =25
b. 35:x
a, 189 - 2.( 93 - x ) = 25
=> 2.( 93 - x ) = 189 - 25 = 164
=> 93 - x = 164 : 2 = 82
=> x = 93 - 82 = 11
290 + 92 = ?
189 + 93 = ?
C1: 3-6-9+12+15-18-21+24+...-90-93+96+99
C2: Tìm x biết:
x + 2 € Ư(3x + 10), x € N.
Tìm x biet:
a,93/17:x+(-21/17):x+22/7:22/3=5/14
b,-32/27-(3x-7/9)^3=-24/27
c,[(3,75:1/4)+12/5.125%)-(7/2.0,8-1,2:3/2)]:(3/2+0,75)x=64
a; \(\dfrac{93}{17}\): \(x\) + (- \(\dfrac{21}{17}\)) : \(x\) + \(\dfrac{22}{7}\): \(\dfrac{22}{3}\) = \(\dfrac{5}{14}\)
\(\dfrac{94}{17}\) \(\times\) \(\dfrac{1}{x}\) - \(\dfrac{21}{17}\) \(\times\) \(\dfrac{1}{x}\) + \(\dfrac{3}{7}\) = \(\dfrac{5}{14}\)
\(\dfrac{72}{17}\) \(\times\) \(\dfrac{1}{x}\) + \(\dfrac{3}{7}\) = \(\dfrac{5}{14}\)
\(\dfrac{72}{17x}\) = \(\dfrac{5}{14}\) - \(\dfrac{3}{7}\)
\(\dfrac{72}{17x}\) = - \(\dfrac{1}{14}\)
17\(x\) = 72.(-14)
17\(x\) = - 1008
\(x\) = - 1008 : 17
\(x\) = - \(\dfrac{1008}{17}\)
Vậy \(x\) \(=-\dfrac{1008}{17}\)
b; - \(\dfrac{32}{27}\) - (3\(x\) - \(\dfrac{7}{9}\))3 = - \(\dfrac{24}{27}\)
- \(\dfrac{32}{27}\) + \(\dfrac{24}{27}\) = (3\(x\) - \(\dfrac{7}{9}\))3
(3\(x-\dfrac{7}{9}\))3 = - \(\dfrac{8}{27}\)
(3\(x-\dfrac{7}{9}\))3 = (- \(\dfrac{2}{3}\))3
3\(x-\dfrac{7}{9}\) = - \(\dfrac{2}{3}\)
3\(x\) = - \(\dfrac{2}{3}\) + \(\dfrac{7}{9}\)
3\(x\) = \(\dfrac{1}{9}\)
\(x\) = \(\dfrac{1}{9}\) : 3
\(x\) = \(\dfrac{1}{27}\)
Vậy \(x=\dfrac{1}{27}\)
Tính nhanh lớp 8:
a, 85^2 - 15^2
b, 93^3 + 21 x 93^2 + 3 x 49 x 93 + 343
c, 73^2 - 13^2 - 10^2 + 20 x 13
d, 97^3 + 83^3/180 - 97 x 83
Tks mọi người :P
a) \(85^2-15^2=\left(85-15\right)\left(85+15\right)=70.100=7000\)
b) \(93^3+21.93^2+3.49.93+343\)
\(=93^3+3.7.93^2+3.7^2.93+7^3\)
\(=\left(93+7\right)^3\)
\(=100^3=1000000\)
c) \(73^2-13^2-10^2+20.13\)
\(=73^2-\left(13^2+10^2-20.13\right)\)
\(=73^2-\left(13-10\right)^2\)
\(=73^2-3^2\)
\(=\left(73+3\right)\left(73-3\right)\)
\(=76.70=5320\)
d) Viết = Latex hộ mình
a) Ta có: \(85^2-15^2\)
\(=\left(85-15\right)\left(85+15\right)\)
\(=70\cdot100=7000\)
b) Ta có: \(93^3+21\cdot93^2+3\cdot49\cdot93+343\)
\(=93^3+3\cdot93^2\cdot7+3\cdot93+7^2+7^3\)
\(=\left(93+7\right)^3\)
\(=100^3=1000000\)
c) Ta có: \(73^2-13^2-10^2+20\cdot13\)
\(=73^2-\left(13^2+10^2-20\cdot13\right)\)
\(=73^2-\left(13^2-2\cdot13\cdot10+10^2\right)\)
\(=73^2-\left(13-10\right)^2\)
\(=73^2-3^2=\left(73-3\right)\left(73+3\right)\)
\(=70\cdot76=5320\)
bài 1 : thục hiện phép tính
20:[24-(32.4-34)2]-20
bài 2: tìm x,biết :
14+5x=46:43
189-2.(93-x)=59
bai 1
20:(24-(3^2.4-34)^2)-20
=20:(24-(9.4-34)^2)-20
=20:(24-2^2)-20
=20:20-20
=-19
bai 2
a
14+5x=4^6:4^3
14+5x=4^3
14+5x=64
5x=64-14
5x=50
x=50:5
x=10
b
189-2.(93-x)=59
2..(93-x)=189-59
2.(93-x)=130
(93-x)=130:2
93-x=65
x=93-65
x=28
1) \(20:\left[24-\left(3^2.4-34\right)^2\right]-20\)
\(=20:\left[24-\left(9.4-34\right)^2\right]-20\)
\(=20:\left[24-4\right]-20\)
\(=20:20-20\)
\(=1-20\)
\(=-19\)
2)a.\(14+5x=4^6:4^3\)
\(14+5x=64\)
\(5x=64-14\)
\(5x=50\)
\(\Rightarrow x=10\)
b) 189-2(93-x)=59
2(93-x) =189-59
2(93-x) =130
93-x =130:2
93-x =65
x =93-65
x =28
Học tốt nha!!!
a,(-299)+ 300+(-101)
b,(-189)+(-200)+(-21)=
Tính hợp lí
a.(-299)+300+(-101)
=\(\left[\left(-299\right)+\left(-101\right)\right]+300\)
=(-400)+300
=(-100)
b.(-189)+(-200)+(-21)
=\(\left[\left(-189\right)+\left(-21\right)\right]+\left(-200\right)\)
=(-210)+(-200)
=(-410)