5x+3x=36:32x4+12
5x+x=39-32
9x-1=9
2x:25=1
1/Rút gọn rồi tính giá trị biểu thức M tại x=1
M= ( x^2 + 1 ) . ( x- 2 ) - ( x+ 2 ) . ( x^2 - 2 x + 4 )
2/ Rút gọn các biểu thức
a. A = ( 3x + 7 ) ^2 + ( 3x + 10) ^2 _ 2(3x+7 ) .(3x+10 )
b/ B= ( x-y) ^2 - 92x^2 - 2y^2 ) + (x+y )^2
c/ C= (x^2 + 1 ) .( x-5 ) - (x-5 ) .(x^2 + 5x + 25 )
a, (2x^3 - 5x^2 - x + 1):( 2x + 1 )
b, ( 4x^3 - 2x^4 + x^5 - 3x^2 + 1 ):( x^2 - 2x + 3 )
c, ( -3x^3 + 7x^2 - 17x + 10 ):( 3x - 1 )
d, ( x^2 - 2x + 1 ):( x - 1 )
e, [ x^2 - 4 + ( x - 2 )^2 ]:( x - 2 )
f, ( 125x^3 + 1 ):( 5x + 1 )
Tìm x biết
A/ 5x-16 =40-1
B/x-10=-25
C/-12+x= -30
D/ 2x +12 = -40+ 6
E/125: (3x-13) =25
F/ 541+(218-x) = 735
G/ 3 (2x+1)-19=14
H/ 175-5 (x+3) = 85
I/ 8x + (-3) =39
L/ 2x+4x=36+(-6)
\(a,5x-16=40-1\)
<=>\(5x=40-1+16\)
<=>\(5x=55\)
<=>\(x=11\)
\(b,x-10=-25\)
<=>\(x=\left(-25\right)-10\)
<=>\(x=-35\)
\(c,-12+x=-30\)
<=>\(x=\left(-30\right)+12\)
<=>\(x=-18\)
a) 5x-16=40-1
5x-16=39
5x=39+16
5x=55
x=55:5
x=11
b)x-10=(-25)
x=(-25)+10
x=(-15)
c) -12+x= -30
x= -30-(-12)
x= -30+12
x= -18
d) 2x +12 = -40+ 6
2x+12=(-34)
2x=(-34)-12
2x=(-46)
x=(-46):2
x=(-23)
e)125:(3x-13)=25
3x-13=125:25
3x-13=5
3x=5+13
3x=18
x=18:3
x=6
f)541+(218-x)=735
218-x=735-541
218-x=194
x=218-194
x= 24
g) 3(2x+1)-19=14
3(2x+1)=14+19
3(2x+1)=33
2x+1=33:3
2x+1=11
2x=11-1
2x=10
x=10:2
x=5
h)175-5(x+3)=85
5(x+3)=175-85
5(x+3)=90
x+3=90:5
x+3=18
x=18-3
x=15
i)8x+(-3)=39
8x=39-(-3)
8x=42
x=42:8
x=42/8
L)2x+4x=36+(-6)
6x=30
x=30:6
x=5
Tìm x
a, (x+2)^3 - x(x^2+6x-3)=0
b,(x+4)^3 - x(x+6)^2=7
c, (x-1)^3 - x(x^2-3x-2)=0
d,1000x^3+90x(10x+3)+27=0
e,125x^3+15x(5x+1)= -1
f, 27x^3+45x(3x+5)+133=0
a, \(\left(x+2\right)^3-x\left(x^2+6x-3\right)=0\Leftrightarrow x^3+4x^2+4x+2x^2+8x+8-x^3-6x^2+3x=0\)
\(\Leftrightarrow15x+8=0\Leftrightarrow x=-\frac{8}{15}\)
b, \(\left(x+4\right)^3-x\left(x+6\right)^2=7\Leftrightarrow12x+64=0\Leftrightarrow x=-\frac{19}{4}\)làm tắt:P
Tự làm nốt nhé
Thu gon da thuc:
\(F\left(x\right)=x^2-3x^3-\sqrt{25}+\frac{1}{2}x-\left(-3x^3+\frac{5x}{2}-\sqrt{36}\right)\)
\(F\left(x\right)=x^2-3x^3-\sqrt{25}+\frac{1}{2}x-\left(-3x^3+\frac{5x}{2}-\sqrt{36}\right)\)
=> \(F\left(x\right)=x^2-3x^3-5+\frac{1}{2}x+3x^3-\frac{5x}{2}+6\)
=> \(F\left(x\right)=x^2+\left(3x^3-3x^3\right)+\left(6-5\right)+\left(\frac{x}{2}-\frac{5x}{2}\right)\)
=> \(F\left(x\right)=x^2+1-2x\)
Cách hiểu 1:[TEX]\frac{44-x}{3}[/TEX]=[TEX]\frac{x-12}{5}[/TEX]
[TEX]\frac{220-5x}{15}[/TEX]=[TEX]\frac{3x-36}{15}[/TEX]
hay 220-5x=3x-36
=220-5x-3x+36=0
=220+36-5x-3x=0
=256-(5x+3x)=0
=256-8x=0
=8x=256
=x=32
Bài 7. Tìm x,biết:
a) x-3x2=0 e) 5x(3x-1)+x(3x-1)-2(3x-1)=0
b) (x+3)2-x(x-2)=13 c) (x-4)2-36=0
d) x2-7x+12=0 g) x2-2018x-2019=0
Bài 8. Tìm x, biết
a) (2x-1)2=(x+5)2 b) x2-x+1/4
c) 4x4-101x2+25=0 d) x3-3x2+9x-91=0
TÌM X BIẾT :
a/ 3x ( 3x -1 ) - ( 3x + 1 ) ( 3x - 1 ) = 0
b/ \(x^2\) - 5x + 25 - 5x = 0
KHÔNG BỎ BƯỚC Ạ !
a: Ta có: \(3x\left(3x-1\right)-\left(3x+1\right)\left(3x-1\right)=0\)
\(\Leftrightarrow9x^2-3x-9x^2+1=0\)
\(\Leftrightarrow3x=1\)
hay \(x=\dfrac{1}{3}\)
b: Ta có: \(x^2-5x+25-5x=0\)
\(\Leftrightarrow\left(x-5\right)^2=0\)
\(\Leftrightarrow x-5=0\)
hay x=5
Tìm x:
1, (5x-1)(5x+1)=25^2-7x+15
2,(3x-5)(x+1)-(3x-1)(x+1)=x-4
1) \(\left(5x-1\right)\left(5x+1\right)=25x^2-7x+15\)
\(\Leftrightarrow25x^2-1=25x^2-7x+15\)
\(\Leftrightarrow7x=16\Leftrightarrow x=\dfrac{16}{7}\)
2) \(\left(3x-5\right)\left(x+1\right)-\left(3x-1\right)\left(x+1\right)=x-4\)
\(\Leftrightarrow3x^2-2x-5-3x^2-2x+1=x-4\)
\(\Leftrightarrow5x=0\Leftrightarrow x=0\)
10x+3/12=1+6:8x/9
2x+7x5 5x+1=0
2x(x-5)-x+5=0
(x+3)^2-(5-x)(x+3)=0
(x+2)(3-4x)=x^2+4x+4
bạn viết rõ đề câu a;b nhé
c, \(2x\left(x-5\right)-\left(x-5\right)=0\Leftrightarrow\left(2x-1\right)\left(x-5\right)=0\Leftrightarrow x=\dfrac{1}{2};x=5\)
d, \(\left(x+3\right)\left(x+3-5+x\right)=0\Leftrightarrow\left(x+3\right)\left(2x-2\right)=0\Leftrightarrow x=-3;x=1\)
e, \(\left(x+2\right)\left(3-4x\right)=\left(x+2\right)^2\Leftrightarrow\left(x+2\right)\left(3-4x-x-2\right)=0\)
\(\Leftrightarrow\left(x+2\right)\left(-5x+1\right)=0\Leftrightarrow x=-2;x=\dfrac{1}{5}\)