=>x2-7x+12=196
=>x2-7x-184=0
=>\(x\in\left\{\dfrac{7+\sqrt{785}}{2};\dfrac{7-\sqrt{785}}{2}\right\}\)
=>x2-7x+12=196
=>x2-7x-184=0
=>\(x\in\left\{\dfrac{7+\sqrt{785}}{2};\dfrac{7-\sqrt{785}}{2}\right\}\)
Thực hiện phép tính:
A) 7/38 x 9/11 +7/38 x 4/11 -7/38 x 2/11
B) 5/31 x 21/25 + 5/31 x -7/10 - 5/31 x 9/20
C) ( -2/3 + 3/7 ) : 4/5 + (-1/3 + 4/7 ) : 4/5
D) 5/9 : ( 1/11 -5/22 ) + 5/9 : ( 1/15 - 2/3 )
E) 3/14 : 1/28 -13/21 : 1/28 + 29/42 : 1/28 - 8
F) ( -40/51 x 0,32 x17/20) : 64/75
Đây là dấu x ( là nhân ) mọi người nhé
mong mn giúp em ạ
|x-3|=7-(-2)
(3x-2^4).7^3=2.7^4
x-[42+(-28)=-8
3/15- x = -1/7
[4,5 + 3/4.x] : 8/3 =9/8
[x-1/4] . 3/28+ 2 và 7/9 = 8 và 7/9
/ là phần nha làm nhanh có quà
tính nhanh
1. 2/3 + 4/9 + 1/5 + 2/15 +3/2 - 17/18
2. 13/28 x 5/12 - 5/28 x 1/12
3. 19/4 x 15/23 - 15/4 x 7/23 + 15/4 x 11/23
a,2.(x-5)-3.(x+7)=14
b,5.(x-6)-2.(x+3)=12
c,-5.(2-x)+4.(x-3)=10.x-15
d,-7.(3x-5)+2.(7.x-14)=28
e,5.(4-x)-7.(-x+2)=4-9+3
f,-4.(2.x+1)+8.(3-2.x)=24
( 7 - x ) - (25 +7) = - 25
x - [42 + ( -28 )] = - 8
|x - 3|= | 5 | + | - 7|
4 - (7 - x) =x - (13 - 4)
x-[42+(-28)=-8
|x-3|=|5|+|-7|
4-(x-7)=x-(13-4)
ai chyên toán giúp mình nha
\(\frac{3}{\left(x-4\right)\left(x-7\right)}+\frac{6}{\left(2-7\right)\left(x-13\right)}+\frac{15}{\left(x-13\right)\left(x-28\right)}-\frac{1}{x-28}=-\frac{1}{20}\)
\(\frac{3}{\left(x-4\right)\left(x-7\right)}+\frac{6}{\left(2-7\right)\left(x-13\right)}+\frac{15}{\left(x-13\right)\left(x-28\right)}-\frac{1}{x-28}=-\frac{1}{20}\)
\(\frac{3}{\left(x-4\right)\left(x-7\right)}+\frac{6}{\left(2-7\right)\left(x-13\right)}+\frac{15}{\left(x-13\right)\left(x-28\right)}-\frac{1}{x-28}=-\frac{1}{20}\)