3(x+2)2+(2x-1)2-7(x-3)(x+3)=36
<--> 3(x2+4x+4)+(4x2-4x+1)-7(x2-9)=36
<--> 3x2+12x+12+4x2-4x+1-7x2+63=36
<-->8x+76=36
<-->8x= -40
<--> x= -5
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Bài 3: Những hằng đẳng thức đáng nhớ
Các câu hỏi tương tự
tìm x biết:
a) (x-3)2-4=0
b) x2-2x=24
c) (x+4)2-(x+1)(x-1)=16
d) (2x+1)2-4(x-1)2=9
e) (x+3)2-(x-4)(x+8)=1
f) (2x-1)2+(x+3)2-5(x+7)(x-7)=0
g) 3(x+2)2+(2x-1)2-7(x+3)(x-3)=36
(x + 2)^2 + (2x -1)^2-(x - 3)^2 = 36
(2x -1)2 + (x + 3)2 - 5(x + 7)(x - 7) = 0
Rút gọn :
1. (2x-5)(3x+1)-(x-3)^2+(2x+5)^2-(3x+1)^3
2. (2x-1)(2x+1)-3x-2)(2x+3)-(x-1)^3+(2x+3)^3
3. (x-2)(x^2+2x+4)-(3x-2)^3+(3x-4)^2
4. (7x-1)(8x+2)-(2x-7)^2-(x-4)^3-(3x+1)^3
5. (5x-1)(5x+1)-(x+3)(x^2-3x+9)-(2x+4)^2-(3x-4)^2+(2x-5)^3
6. (4x-1)(x+2)-(2x+5)^2-(3x-7)^2+(2x+3)^3=(3x-1)^3
tim x biet
(x+1)2+(x-2)^3-2x^2(x-1,5)=3
tim x:a,(x+3)3-x(3x+1)2+(2x+1)(4x2-2x+1)=28
b,(x-2)3-(x-3)(x2+3x+9)+6(x+1)2=49
2 tháng 10 2020 lúc 18:48
a)(2x-1)^2+(x+3)^2-5(x+7)(x-7)=0
b)(x+2)(x^2-2x+4)-x(x^2+2)=15
c)(x+3)^3-x(3x+1)^2+(2x-1)(4x^2-2x+1)=28
d)(x^2-1)^3-(x^4+x^2+1)(x^2-1)=0
30 tháng 9 2020 lúc 20:04
a)(2x-1)^2+(x+3)^2-5(x+7)(x-7)=0
b)(x+3)^3-x(3x+1)^2+(2x-1)(4x^2-2x+1)=28
c)(x+2)(x^2-2x+4)-x(x^2+2)=15
d)(x^2-1)^3-x^4+x^2+1)(x^2-1)=0
giúp mình nhé!
tìm x biết
phần a: (2x+1)^2= 25 ; (2x-3)^2= 36
phần b: 5^x+2= 625 ; (2x -1)^3= -8
phần c: (x-3)^2+(15x-45)^4= 0 ; |x-3|+(x^2-3x)^2= 0
1, tìm x :
a) (x+2).(x+3)-(x-2).(x+5)=0
b) (2x+3).(x-4)+(x-5).(x-2)=(x-4).(3x-5)
c) (3x-5).(7-5x)-(5x+2).(2-3x)=3
d)(x-7).(x+7)-(x-4)2-x=10+3
e) (x+1/2)2-(x-1).(x+1)=2x-1
2, Thu gọn :
a) (x+5)2-(3-x)2-2(x-4).(x+4)
b)4(x-1)2+(2x+3)2-8(x-2)(x+2)