A= (-1/3)^-1 - (-6/7)^0 + (1/2)^2 :2
B= [(0,1)^2]^0 + [(1/7)^-1]^2 x 1/49 x [(2^2)^3 : 2^5]
1.Tìm x thuộc Z:
a) (x-2)(x+1)=0
b) (x^2 +7).(x^2 -49)<0
c) (x^2 -7).(x^2 -49)<0
2. Tính, tính hợp lí:
a) (-55).(-25).(-8)
b) (-1).(-2).(-3).(-4).(-5).10
c) (-1).(-2)-(-3).(-4).(-2).(-3)
d) (-2).(-3):(-1)-(-3):(-6)+(-2)
1a) (x-2)(x+1)= 0
Suy ra \(\orbr{\begin{cases}x-2=0\\x+1=0\end{cases}}\)Suy ra \(\orbr{\begin{cases}x=2\\x=-1\end{cases}}\)
Bài 1: Tìm x :
a. ( x + 4 )2 - ( x + 1 ) ( x - 1 ) = 16
b. ( 2x - 1 )2 + ( x + 3 )2 - 5 ( x + 7 ) ( x - 7 ) = 0
c. ( x - 2 )3 - ( x - 3 ) ( x2 + 3x + 9 ) + 6 ( x + 1 )2 = 49
Bài 1: Tìm x :
a. ( x + 4 )2 - ( x + 1 ) ( x - 1 ) = 16
b. ( 2x - 1 )2 + ( x + 3 )2 - 5 ( x + 7 ) ( x - 7 ) = 0
c. ( x - 2 )3 - ( x - 3 ) ( x2 + 3x + 9 ) + 6 ( x + 1 )2 = 49
bài 7 tìm x
1,x(x+3)-5(x+3)=0 2,5x(x-1)=x-1
3,(x+1)=(x+1)\(^2\) 4,x(2x-3)-2(3-2x)=0
5,\(\left(x-2\right)^2-4=0\) 6,\(36x^2=49\)
7,\(2x\left(x-6\right)-x+6=0\) 8,\(3x\left(2x-1\right)-24x+12=0\)
9,\(x^2-6x+8=0\) 10,\(x^2+2x-15=0\)
1: =>(x+3)(x-5)=0
=>x=5 hoặc x=-3
2: =>(x-1)(5x-1)=0
=>x=1/5 hoặc x=1
5: =>(x-4)*x=0
=>x=0 hoặc x=4
10: =>(x+5)(x-3)=0
=>x=3 hoặc x=-5
9: =>(x-2)(x-4)=0
=>x=2 hoặc x=4
7: =>(x-6)(2x-1)=0
=>x=1/2 hoặc x=6
8: =>(2x-1)(3x-12)=0
=>x=4 hoặc x=1/2
Bài 1 Tính
a,(1/3)^-1 - (-6/7)^0 +(1/2)^2:2
b,[(0,1)^2]^0+[1/7^-1]^2 x 1/49 x [(2^2)^3:2^5]
Bài 2 Tìm số nguyên n biết
a,1/9 x 27^n=3^n
b,3^-2 x 3^4 x 3^n =3^7
c,2^-1 x 2^n 4 x 2^-n=9 x 2^5
d,32^-n x 16^n=2048
e, (n-2)^1=16
f, (2n+1)^3=-27
giải chi tiết hộ mk nhé
giải luôn hộ mk hnay mk phải đi học r
Tìm x,y biết :
a) 1-(5/3/8+x-7/5/24): 16/2/3=0
b) (1/6+2/1/12-10,75).x-7= (2/5+3/8-2,225): 0,1
người ta ko bt thì hỏi , đừng có mak ns mấy câu vô văn hóa thế nhá
((0,1)^2)^0+((1/7)^-1)^2.1/49 ((2^2)^3 :2^5
1,-15(x+2)+7(2x-3)
2,x^2+2x=0
3,(-2x)(-4x)+28=100
4,(2x-5)^2-49=0
5,/x-5/+/y-3/=1
6,3×(x-2)-6(x-5)=2(5-2x)
7, 5x ×(-x)^2+1=0
8,4x^3=4x
Tìm x biết:
a) (x+2)^2 - 9 = 0
b) 25x^2 - 10x + 1 = 0
c) x^2 + 14x + 49 = 0
d) (2x-1)^2 + (x+3)^2 - 5(x+7) (x-7) = 0
a)
\(\left(x+2\right)^2-9=0\)
\(\Rightarrow\left(x+2\right)^2=9=3^2\)
\(\Rightarrow x+2=\pm3\)
\(\Rightarrow x=-5;1\)
b)
\(25x^2-10x+1=0\)
\(\left(5x\right)^2-2\cdot5x+1^2=0\)
\(\Rightarrow\left(5x+1\right)^2=0\)
\(\Rightarrow5x+1=0\)
\(\Rightarrow5x=-1;x=\dfrac{-1}{5}\)
c)
\(x^2+14x+49=0\)
\(\Rightarrow x^2+2\cdot7x+7^2=0\)
\(\Rightarrow\left(x+7\right)^2=0;x+7=0\)
\(\Rightarrow x=-7\)
d)
\(\left(2x-1\right)^2+\left(x+3\right)^2-5\left(x+7\right)\left(x-7\right)=0\)
\(4x^2-4x+1+x^2+6x+9-5x^2+5\cdot49=0\)
\(\Rightarrow5x^2-5x^2-4x+6x+10+245=0\)
\(\Rightarrow2x+255=0\)
\(\Rightarrow2x=-255\)
\(\Rightarrow x=\dfrac{-255}{2}\)