a, \(\left(2x-7\right)^2+\left(2x+7\right)^2-2\left(2x+7\right)\left(2x-7\right)=\left(2x-7-2x-7\right)^2=\left(-14\right)^2=196\)
b, \(\left(5x-3\right)^2-\left(5x+3\right)^2-15\left(2x-1\right)\)
\(=\left(5x-3-5x-3\right)\left(5x-3+5x+3\right)-15\left(2x-1\right)\)
\(=-6.10x-15\left(2x-1\right)\)
\(=-60x-15\left(2x-1\right)=-15\left(4x+2x-1\right)=-15\left(6x-1\right)=-90x+15\)
Bài 1: Rút gọn
A=(7-2x)(7+2x)+(2x+7)2
B=(4x-5)2-(2x-1)(8x-5)
C=(5x-3)2-2(5x-3)(5-5x)+(5x-5)2
D=(2a+3b-c)(2a-3b+c)-(4a2-9b2-c2)
Bài 1: Rút gọn
A=(7-2x)(7+2x)+(2x+7)2
B=(4x-5)2-(2x-1)(8x-5)
C=(5x-3)2-2(5x-3)(5-5x)+(5x-5)2
D=(2a+3b-c)(2a-3b+c)-(4a2-9b2-c2)
tìm x biết
a) 5x(2x-7)+2x(8-5x)=5
b)(3x-5)(7-5x)-(5x+2)(2-3x)=4
c)5(2x-3)^2-5(x+1)^2-15(x+4)(x-4)=-10
d) 5x(x-3)(x+3)-(2x-3)^2 -5(x+2)^3+34x(x+2)=1
Giải phương trình sau :
a,\(\dfrac{7-3x}{12}+\dfrac{5x+2}{7}=x+13\)
b,\(\dfrac{3\left(x+3\right)}{4}-\dfrac{1}{2}=\dfrac{5x+9}{7}-\dfrac{7x-9}{4}\)
c,\(\dfrac{2x+1}{3}-\dfrac{5x+2}{7}=x+3\)
d,\(\dfrac{2x-3}{3}-\dfrac{2x+3}{7}=\dfrac{4x+3}{5}-17\)
d) (3x – 5)(7 – 5x) – (5x + 2)(2 – 3x) = 4 g) 3(2x - 1)(3x - 1) - (2x - 3)(9x - 1) =0 j) (2x – 1)(3x + 1) – (4 – 3x)(3 – 2x) = 3 k) (2x + 1)(x + 3) – (x – 5)(7 + 2x) = 8 m) 2(3x – 1)(2x + 5) – 6(2x – 1)(x + 2) = - 6
1) 2x – (3 – 5x) = 4( x +3)
2) 5(2x-3) - 4(5x-7) =19 - 2(x+11)
3) 5x - 4(6-x)(x + 3) = (4-2x)(3-2x) + 2
4) (x - 1)3 - (3x + 2)(-12) = (x2 + 1)(x - 2) - x2
5) (3x -1)2 - (x +3)(2x-1) = 7(x + 1)(x -2) -3x
mn giúp mình vs
Tìm x:
a) 4x(3x-7)-6(2x^2-5x+1)=12
b) (5x+3)(4x-1)+(10x-7)(-2x+3)=27
c) (8x-5)(3x+2)-(12x+7)(2x-1)=17
d) (5x+9)(6x-1)-(2x-3)(15x+1)=-190
A) 2x³+6x²=x²+3x
B) (2x+5)²=(x+2)²
C) x²-5x+6=0
D) (2x-7)²-6(2x-7)(x-3)=0
E) (x-2)(x+1)=x²-4
G) 2x(2x-3)=(3-2x)(2-5x)
H) (1-x)(5x+3)=(3x-7)(x-1)
F) (x+6)(3x-1)+x+6=0
I) (4x-1)(x-3)=(x-3)(5x+2)
K) (x+4)(5x+9)-x-4=0
H) (x+3)(x-5)+(x+3)(3x-4)=0
M) (2x+3)(-x+7)=0
1).(4-3x)(10-5x)=0 2).(7-2x)(4+8x)=0 3).(9-7x)(11-3x)=0
4).(7-14x)(x-2)=0 5).(\(\dfrac{7}{8}\)-2x)(3x+\(\dfrac{1}{3}\))=0 6).3x-2x\(^2\)
7).5x+10x\(^2\)
