\(=\left(9x^2+24x+16\right)-\left(9x^2-1\right)=9x^2+24x+16-9x^2+1=24x+17\)
\(=\left(9x^2+24x+16\right)-\left(9x^2-1\right)=9x^2+24x+16-9x^2+1=24x+17\)
tính
\(\dfrac{x^2+38x+4}{2x^2+17x+1}-\dfrac{3x^2-4x-2}{2x^2+17x+1}\)
\(\dfrac{3x+1}{3x^2-3x+1}+\dfrac{x^2-6x}{x^2-3x+1}\)
\(\dfrac{-x}{3x-2}+\dfrac{7x-4}{3x-2}\)
Giải PT
1 ) (2x + 1)(3x – 2) = (5x – 8)(2x + 1)
2) 4x2 -1 = (2x + 1)(3x – 5)
3) (x + 1)2 = 4(x2 – 2x + 1)
4) 2x3+ 5x2 – 3x = 0
5) {2x{ = 3x – 2
6) x + 15 = 3x – 1
7) 2 – x = 0,5x – 4
Rút gọn các biểu thức sau:
a,(3x+1)^2-2(3x+1)(3x-5)+(3x-5)^2
b,(3x^2-y)^2
c,(3x+5)^2+(3x-5)^2-(3x+2)(3x-2)
d,2x(2x-1)^2-3x(x+3)(Õ-3)-4x(x+1)^2
e,(x-2)(x^2+2x+4)-(x+1)^2+3(x-1)(x+1)
f,(x^4-5x^2+25)(x^2+5)-(2+x^2)^2+3(1+x^2)^2
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)3x^2-9 2)1/2x^2-2y^2 3)3x^2-12y^2 4)1/3x^2y^2-3x^2
Giải phương trình:
a) \(\dfrac{x+5}{3x-6}-\dfrac{1}{2}=\dfrac{2x-3}{2x-4}\)
b) \(\dfrac{12}{1-9x^2}=\dfrac{1-3x}{1+3x}-\dfrac{1+3x}{1-3x}\)
c) \(\dfrac{x+1}{x-2}-\dfrac{5}{x+2}=\dfrac{12}{x^2-4}+1\)
Bài 2: (2 điểm) Tìm x, biết:
a) (3x + 4)2 – (3x – 1)(3x + 1) = 49
b) x2 – 4x + 4 = 9(x – 2)
c) x2 – 25 = 3x - 15
d) (x – 1)3 + 3(x + 1)2 = (x2 – 2x + 4)(x + 2)
Giải phương trình:
a) 5 + 96/x2-16 = 2x-1/x+4 - 3x-1/4-x
b) 3x+2/3x-2 - 6/2+3x = 9x2/9x2-44
c) 1/x-1 + 1/x+1 = 2/x+2
d) x+1/x-2 - 5/x+2 = 12/x2-4 + 1
Tìm x :( bài 14 trang 11 sách bồi dưỡng năng lực tự học toán 8)
Câu 2 : (2x+3)2+(x-1)*(x+1)=5*(x+2)2-(x-5)*(x+1)+(x+4)2
Câu 3 : (-x+5)*(x-2)+(x-7)*(x+7)=(3x+1)2-(C)*(3x+2)
Câu 4 : (5x-1)*(x+1)-2(x-3)2=(x+2)*(3x-1)-(x+4)2+(x2-x)
Câu 5 : (4x-1)2-(3x+2)*(3x-2)=(7x-1)*(x+2)+(2x+1)2-(3x+2)
Câu 6 : (2x+3)2-(5x-4)*(5x+4)=(x+5)2-(3x-1)*(7x+2)-(x2-1+1)
Câu 7 : (1-3x)2-(x-2)*(9x+1)=(3x-4)*(3x+4)-9(x+3)2
Câu 8 : (3x+4)*(3x-4)-(2x+5)=(x-5)+(2x+1)2-(x2-2x)+(x-1)2
Câu 9 : (x-7)*(x+1)-(x-3)2=(3x-5)*(3x+5)-(3x+1)+(x-2)2-x2
Câu 10 : -5(x+3)2+(x-1)*(x+1)+(2x-3)=(5x-2)2-5x(5x+3)