TINH NHANH : A = 8 x 321 x 3 + 6 x 678 x 4 + 24 ; B = 1234 x 6789 x (650 - 325 x 2 )
1. tinh :
a) 15/8 + 3/4 - 5/12
b) 11/24 x 12/33 + 5/6
c) 15/8 + 7/24 : 5/8
2 . tim x, biet :
a) x + 5/8 : 3/4 = 17/9
b) x - 5/9 x 18/15 = 1/3
c) x x7/8 - 5/8 = 13/24
d) X x1/7 + X x 1/4 + X x 1/4 =18
giup mik nhanh nha. mik can gap lam
a)15/8+3/4-5/12
=45+18-10/24
=53/24
b)11/24.12/33+5/6
=11.12/12.2.11.3+5/6
=1/6+5/6
=6/6=1
c)15/8+7/24:5/8
=15/8+7/24.8/5
=15/8+7.8/3.8.5
=15/8+7/15
=đề sai, nếu đúng thì như này
=8/15+7/15
=15/15=1
tinh nhanh; 8 x 427 x 3 + 6 x 573 + 46 x 1235 x 20 - 5 x 235 x 24
\(8\cdot427\cdot3+6\cdot573+46\cdot1235\cdot20-5\cdot235\cdot24\)
\(=4\cdot2\cdot427\cdot3+6\cdot573+23\cdot2\cdot1235\cdot20-5\cdot235\cdot4\cdot3\cdot2\)
\(=4\cdot427\cdot6+6\cdot573+23\cdot2\cdot247\cdot5\cdot20-20\cdot5\cdot47\cdot3\cdot2\)
\(=6\cdot\left(4\cdot427+573\right)+23\cdot247\cdot200-47\cdot3\cdot200\)
\(=6\cdot\left(1708+573\right)+23\cdot\left(200+47\right)\cdot200-47\cdot3\cdot200\)
\(=6\cdot2281+23\cdot200\cdot200+23\cdot47\cdot200-47\cdot3\cdot200\)
\(=13686+23\cdot40000+20\cdot200\cdot47\)
\(=13686+920000+4000\cdot47\)
\(=13686+920000+188000\)
\(=13686+\left(920000+188000\right)\)
\(=13686+1108000=1121686\)
trời ơi là trời
làm đúng mà dis
mệt quá là mệt
thằng mô dis tui hử khai mau
tui dis hết luôn cho mà coi
Tinh gia tri cua phan so: A= 2 x 3 + 2 x 4 x 8 + 4 x 8 x 16 + 8 x 16 x 32/ 3x 4 + 2 x 6 x 8 + 4 x 12 x 16 + 8 x 24 x 32
a)0,92% x 324 + 0,92% x 678 tinh nhanh
b)4,9% x 3,3 - 4,8% x 3,3 tinh nhanh
giai ra giup mik voi a
A)
0,92 × 324 + 0,92 × 678
= 0,92 × (324+678)
= 0,92 × 1002
= 0,92 × 1000 + 0,92 × 2
= 920 + 1,84
= 921,84
a)
tinh nhanh
I = 4/3 x 9/8 x 16/15 x 25/24 x .......x 100/99
Tìm x, biết:
a, 3/8=6/x
b, 1/8=x/27
c, 4/x=6/8
d, x/6=5/24
làm nhanh mình tick nhé!
a, \(\frac{3}{8}=\frac{6}{x}\Rightarrow3x=6.8\Rightarrow3x=48\Rightarrow x=\frac{48}{3}=16\)
b, \(\frac{1}{8}=\frac{x}{27}\Rightarrow8x=27\Rightarrow x=\frac{27}{8}\)
c, \(\frac{4}{x}=\frac{6}{8}\Rightarrow6x=4.8\Rightarrow6x=32\Rightarrow x=\frac{32}{6}=\frac{16}{3}\)
d, \(\frac{x}{6}=\frac{5}{24}\Rightarrow24x=30\Rightarrow x=\frac{30}{24}=\frac{5}{4}\)
Giúp mình với nhanh nhanh nhé, cảm ơn a) ( x^2 + x )^2 + 2( x^2 + x ) - 8 = 0 b) ( x^2 - 4x +3 ) ( x^2 +6x + 8 ) + 24 = 0 c) 6x^4 + 25x^3 + 12x^2 - 25x + 6 = 0 d) ( x - 2 )^4 + ( x- 3 )^4 = 0
a: \(\left(x^2+x\right)^2+2\left(x^2+x\right)-8=0\)
\(\Leftrightarrow\left(x^2+x+4\right)\left(x^2+x-2\right)=0\)
\(\Leftrightarrow\left(x+2\right)\left(x-1\right)=0\)
hay \(x\in\left\{-2;1\right\}\)
b: \(\Leftrightarrow\left(x-1\right)\left(x-3\right)\left(x+2\right)\left(x+4\right)+24=0\)
\(\Leftrightarrow\left(x^2+x-2\right)\left(x^2+x-12\right)+24=0\)
\(\Leftrightarrow\left(x^2+x\right)^2-14\left(x^2+x\right)+48=0\)
\(\Leftrightarrow\left(x^2+x-6\right)\left(x^2+x-8\right)=0\)
hay \(x\in\left\{-3;2;\dfrac{-1+\sqrt{33}}{2};\dfrac{-1-\sqrt{33}}{2}\right\}\)
tính nhanh 1/24 x 3/18 + 1/4 x 3/8 x 1/6 - 1/8 x 1/8 x 1/3 giúp mình với