(x+1)+(x+2)+(x+3)+(x+4)+......+(x+30)=756
\(\Rightarrow\)(x+x+x+.....+x)+(1+2+3+....+30)=756
\(\Rightarrow\)30x+465=756
\(\Rightarrow\)30x=291
\(\Rightarrow\)x=9,7
Tìm x
1). 2x+2 - 2x+1 = 32
2). 3x+5 + 3x+2 = 756
Cho x y thỏa mãn x+y+1/x+1/y=8
x^2+y^2+1/x^2+1/y^2=30
Tính P=x^3+y^3+1/x^3+1/y^3
a) 1 + 2+3+...+x=210
b) x + (x+1)+(x+2)+....+(x+30)=1240
tìm x
1, Tìm x biết :
a, | x - 4 | - 15 = -9
b, 21 - | x + 6 | = -13
c, x - [ x - ( - x +1)]=1
d, 17 - { - x - [ - x - ( - x )]} = - 16
2, Tính tổng :
a, ( - 125 ) + 100 - 80 + 125 - 20
b, - 30 - [ 95 + ( - 40 ) + 5 + ( -30)]
3, So sánh P và Q biết :
P = a - {( a - 3) - [( a + 3) - ( - a - 2)]}
Q = [ a + ( a + 3) ] - [ ( a + 2)-(a-2)]
a) Tính A = ( 1 - \(\dfrac{1}{2}\) )( 1 - \(\dfrac{1}{3}\) ) (1-\(\dfrac{1}{4}\) ) ....(1-\(\dfrac{1}{2014}\) ) (1-\(\dfrac{1}{2015}\) ) (1-\(\dfrac{1}{2016}\) )
b)Tìm x biết \(\dfrac{x-2}{12}\) + \(\dfrac{x-2}{20}\) + \(\dfrac{x-2}{30}\)+ \(\dfrac{x-2}{42}\) + \(\dfrac{x-2}{56}\) +\(\dfrac{x-2}{72}\) = \(\dfrac{16}{9}\)
bài 1 tìm x
a)-12(x-5)+7(3-x)=5
b)30(x+2)-6(x-5)-24x=100
bài 2 tìm x,y
a)(x-3)(2y+1)=7
b)(2x+1)(3y-2)=-55
Bài 1: Tìm x,y
a, -3.x -30 = -60
b, x.y = 7
c, ( x-1 ). ( y+2 ) = -5
d, 2.x -3 = 5.x -7
e, ( -2 )2 - 8.x = 20
f, 17- ( -31 ) + 3.x = 2x - ( -50 )
g, 2. y2 - 16 = 34
tìm x thỏa mãn: 30+29+28+...+2+1=(1+2+3+4+5).x
12 x 56 x 2 + 6 x 14 x 4 + 3 x 30 x 8
