4x2 - 25 - (2x - 5)(2x + 7) = 0
<=> (2x)2 - 52 - (2x - 5)(2x + 7) = 0
<=> (2x - 5)(2x + 5) - (2x - 5)(2x + 7) = 0
<=> (2x - 5)(2x + 5 - 2x - 7) = 0
<=> (2x - 5) . (-2) = 0
<=> 2x - 5 = 0
<=> 2x = 5
<=> x = 5/2
Các câu hỏi tương tự
Tìm x biết 2(x+3)-x^2-3x=0
x^3+27+(x+3)(x-9)=0
4x^2-25-(2x-5)(2x+7)=0
8x^3-50x=0
(2x-1)^2-25=0
Tìm x biết :
a, (x-2).(x2 +2x +7) +2.( x2-4) -5 .(x-2) =0
b, 4x2 -25 -(2x-5) .(2x+7) =0
c, x3 +27 + (x+3) .(x-9)=0
Tìm x:
a) 4x^2 - 25 - ( 2x - 5) .( 2x + 7) = 0
b) x^3 + 27 + ( x+3). ( x -9) = 0
Tìm x, biết
1)4x2-25-(2x-5)(2x+7)=0
2)x3+27+(x+3)(x-9)=0
Tìm x, biết:a) 3x(x - 1) + x - 1 0;b) (x - 2)(
x
2
+ 2x + 7) + 2(
x
2
- 4) - 5(x - 2) 0;c)
(
2
x
-
1
)
2
- 25 0;d)
x
3
+ 27 + (x + 3)(x - 9) 0.
Đọc tiếp
Tìm x, biết:
a) 3x(x - 1) + x - 1 = 0;
b) (x - 2)( x 2 + 2x + 7) + 2( x 2 - 4) - 5(x - 2) = 0;
c) ( 2 x - 1 ) 2 - 25 = 0;
d) x 3 + 27 + (x + 3)(x - 9) = 0.
tìm x
\(4x^2-25-\left(2x-5\right)\left(2x+7\right)=0\)
tìm x
a. 4(2x+7)2 -9(x+3)2
b. 3x(x+5) -2x-10=0
c. x3-9x=0
d. (5+2x)(2x-7)=4x2-25
e.x2-11x+30=0
Giúp mình với !!!
Tìm x:
a) (x-20) mũ 2 -(x+1)(x+3)=-7
b) (3x+5)(4-3x)=0
c) x mũ 3 -9x=0
d)2/3x (x mũ 2 -4)=0
e) (2x+1)-x(2x+1)=0
f)(2x-1) mũ 2 -(2x+5) (2x-5) =18
g)x mũ 2 -25 =6x-9
Tìm x biết:
4x2-8x+4=2(1-x)(x+1)
4x2-25-(2x-5)(2x+7)=0
8x2+30x+7=0
x2+3x-18=0