`3(x+7)+28=9-2(x+5)`
`=>3x+21+28=9-2x-10`
`=>3x+2x=9-10-21-28`
`=>5x=-50``
`=>x=-10`
3(x+7)+28=9-2(x+5)
<=>3x+21+28=9-2x-10
<=>3x+2x=9-10-21-28
<=>5x=-50
<=> x=-10
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
Tìm x:
a) |x+2|=0
b) |x-5|=|-7|
c) |x-3|=7-(-2)
d) (7-x) - (25+7)=-25
e) x-[42+(-28)]=-8
f) |x-3|=|5|+|-7|
h) 9x-1=9
g)3×=9
h
Tìm x:
a) \(\dfrac{-3}{7}\).x=\(\dfrac{3}{56}\).\(\dfrac{28}{9}\)
b) x-\(\dfrac{3}{16}\)=\(\dfrac{7}{15}\):\(\dfrac{3}{5}\)
c) \(\dfrac{2}{5}\)+\(\dfrac{1}{5}\).x=\(\dfrac{5}{6}\)
d) \(\dfrac{3}{4}\)x-\(\dfrac{2}{5}\)x=\(\dfrac{3}{7}\).\(\dfrac{1}{6}\)+\(\dfrac{5}{7}\).\(\dfrac{1}{6}\)
*Lưu ý: Trình bày chi tiết kết quả.
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
Tìm x€Z biết:
a)-218-(x+31)=x-29
B)-12(x-5)+7(3-x)=5
C)3(x+7)+28=9-2(x+5)
D)2(x+3)-3(x-5)=4(3-x)-18
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
tính nhanh các hỗn số , phân số .... sau:
A = 11 3/13 -(2 và 4/7 +5 3/13)
B = 6 4/9 + 3 7/11)-4 4/9
C = -5/7 x 2/11 + -5/7 x 9/11 +1 5/7
D = 0,7 x 2 2/3 .20 x0,375 x5/28
Bài toán 3 : Tìm x, biết.
a. 2(x – 5) – 3(x + 7) = 14 b. 5(x – 6) – 2(x + 3) = 12
c. 3(x – 4) – (8 – x) = 12 d. -7(3x – 5) + 2(7x – 14) = 28
e. 5(3 – 2x) + 5(x – 4) = 6 – 4x f. -5(2 – x) + 4(x – 3) = 10x – 15
g. 2(4x – 8) – 7(3 + x) = |-4|(3 – 2) h. 8(x – |-7|) – 6(x – 2) = |-8|.6 – 50
k. -7(5 – x) – 2(x – 10) = 15 l. 4(x – 1) – 3(x – 2) = -|-5|
m. -4(x + 1) + 89x – 3) = 24 n. 5(x – 30 – 2(x + 6) = 9
o. -3(x – 5) + 6(x + 2) = 9 p. 7(x – 9) – 5(6 – x) = – 6 + 11x
q. 10(x – 7) – 8(x + 5) = 6.(-5) + 24
tìm x thuộc z ,biết
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
