tim x
2/9 * x= 6/11
ko can rut gon
Cho cac phan so 5 / 7, 6 / 9 , 12 / 24 , 23 / 24 va 6 / 14
a Tim phan so toi gian
b Phan so nao rut gon duoc . Hay rut gon
ai nhanh nhat minh TICK cho
Phân số tối giản là: 5/7, 23/24
Phân số rút gọn là: 6/9, 12/24, 6/14
6/9=2/3 12/24=1/2 6/14=3/7
Phân số tối giản là \(\frac{5}{7};\frac{23}{24}\)
Phân số rút gọn được là \(\frac{6}{9};\frac{12}{24};\frac{6}{14}\)
Rút gọn \(\frac{6}{9}=\frac{2}{3};\frac{12}{24}=\frac{1}{2};\frac{6}{14}=\frac{3}{7}\)
1) CMR: 543-54 khong la so chinh phuong
2) Tim x:
2(x-2).(x+3)-x2+4=0
3) Rut gon
a)2(x+1)2-3(x-1)2+(x+2).(5-x)
b)(3x-1)3+(3x-1)3-6x2+9
4) A= (x-5).(x+2)+3.(x-2).(x+2)-(3x-1)2+5x2
a) rut gon A
b) tinh a khi x =1/2
\(2\left(x-2\right)\left(x+3\right)-x^2+4=0\)
\(2\left(x^2+3x-2x-6\right)-x^2+4=0\)
\(2x^2+6x-4x-12-x^2+4=0\)
\(x^2+2x-8=0\)
\(x^2+4x-2x-8=0\)
\(x\left(x+4\right)-2\left(x+4\right)=0\)
\(\left(x+4\right)\left(x-2\right)=0\)
\(\Rightarrow\orbr{\begin{cases}x+4=0\rightarrow x=\left(-4\right)\\x-2=0\rightarrow x=2\end{cases}}\)
3/
a/ \(2\left(x+1\right)^2-3\left(x-1\right)^2+\left(x+2\right)\left(5-x\right)\)
\(=2\left(x^2+2x+1\right)-3\left(x^2-2x+1\right)+\left(5x-x^2+10-2x\right)\)
\(=2x^2+4x+2-3x^2+6x-3+5x-x^2+10-2x\)
\(=-2x^2+13x+9\)
b/ \(\left(3x-1\right)^3+\left(3x-1\right)^3-6x^2+9\)
\(=2\left(3x-1\right)^3-6x^2+9\)
\(=2\left(\left(3x\right)^3-3\left(3x\right)^2\cdot1+3\cdot3x\cdot1-1\right)-6x^2+9\)
\(=2\left(27x^3-27x^2+9x-1\right)-6x^2+9\)
\(=54x^3-54x^2+18x-2-6x^2+9\)
\(=54x^3-60x^2+18x+7\)
Số hơi dài, nên dễ tính sai -,- tính mik hay cẩu thả có j sai ibbb ạ
2) 2.(x - 2).(x + 3) - x2 + 4 = 0
<=> x2 + 2x - 8 = 0
<=> (x - 2).(x + 4) = 0
x - 2 = 0 hoặc x + 4 = 0
x = 0 + 2 x = 0 - 4
x = 2 x = -4
=> x = 2 hoặc x = -4
3) a) 2.(x + 1)2 - 3.(x - 1)2 + (x + 2).(5 - x)
= 2.(x2 + 2x + 1) - 3.(x2 - 2x + 1) + (x + 2).(5 - x)
= 2x2 + 4x + 2 - 3x2 + 6x - 3 + (x + 2).(5 - x)
= 2x2 + 4x + 2 - 3x2 + 6x - 3 + 3x - x2 + 10
= (2x2 - 3x2 - x2) + (4x + 6x + 3x) + (2 - 3 + 10)
= -2x2 + 13x + 9
b) (3x - 1)3 + (3x - 1)3 - 6x2 + 9
= 2.(3x - 1)3 - 6x2 + 9
= 2.(27x3 - 27x2 + 9x - 1) - 6x2 + 9
= 54x3 - 54x2 + 18x - 2 - 6x2 + 9
= 54x3 + (-54x2 - 6x2) + 18x + (-2 + 9)
= 54x3 - 60x + 18x + 7
4) a) A = (x - 5).(x + 2) + 3.(x - 2).(x + 2) - (3x - 1)2 + 5x2
A = (x - 5).(x + 2) + 3.(x - 2).(x + 3) - (9x2 - 6x + 1) + 5x2
A = x2 - 3x - 10 + 3x2 - 12 - (9x2 - 6x + 1) + 5x2
A = x2 - 3x - 10 + 3x2 - 12 - 9x2 + 6x - 1 + 5x2
A = (x2 + 3x2 - 9x2 + 5x2) + (-3x + 6x) + (-10 - 12 - 1)
A = 3x - 23 (1)
b) Thay x = 1/2 vào (1), ta có:
A = 3x - 23 = 3.(1/2) - 23
= 3/2 - 23
= -43/2
A khi x = 1/2 là -43/2
cho ps a\b rut gon 3\5 neu them 6 vao mau giu nguyen tu ta duoc 1 ps moi rut gon =2\3 tim ps a\b
rut gon cac so bang so mu
9 x 9 x 9 x 9
10 x 10 x 10 x 10
2 x2 x2 x3 x3
ai tick minh minh
tick lại cho
9x9x9x9=9^4
10x10x10x10=10^4
2x2x2x3x3=2^3x3^2
9 x 9 x 9 x 9 = 9^4
10 x 10 x 10 x 10 = 10^4
2 x 2 x 2 x 3 x 3 = 2^3 x 3^2
Tíc
Tong TS va MS cua 1 phan so =88 . Sau khi rut gon ta duoc phan so 5/6 . Tim phan so ban dau ?
Cac bn giup Mk voi mk can gap
Ta có sơ đồ:
MS /..................../..................../..................../..................../..................../..................../
TS /..................../..................../..................../..................../..................../ 88
Tử số phân số đó là:
88 : (5 + 6) x 5 = 40
Mẫu số phân số đó là:
88 - 40 = 48
Vậy phân số đó là 40/48
Đáp số: 40/48
cho bieu thuc Q=[(x+1/x)^3-(x^6+1/x^6)-2]:[(x+1/x)^3+x^3+1/x^3].rut gon Q va tim min Q
A=1(x+3) - | 3x+2 |
a)rut gon A
b)tim x de A=5
Mik can rat gap giup mik di mik tick cho :(
a)th1:x+3-3x+2=(-2x)+5
th2:x+3+3x+2=4x+5
b)x=0
rut gon
can 16a^4b^6 / can 128a^6b^6 (a<0, bkhac 0)
\(\frac{\sqrt{16a^4b^6}}{\sqrt{128a^6b^6}}=\sqrt{\frac{16a^4b^6}{128a^6b^6}}=\sqrt{\frac{1}{8a^2}}=\frac{\sqrt{1}}{\sqrt{8a^2}}=\frac{1}{\sqrt{2}\sqrt{4}\sqrt{a}}\)
=\(\frac{1}{2\sqrt{2}a}\)
C= 3 / 1 x 1 x 2 x1 + 5 / 2 x2 x 3x2 +...+19 / 9 x9 x 10 x10 . Rut gon C