Bài tập 48 trang 16 SBT Toán 7 Tập 1

Ta thừa nhận tính chất sau đây: Với a # 0, a # ± 1, nếu $a^m=a^n$ thì m = n. Dựa vào tính chất này, hãy tìm các số tự nhiên m và n, biết

a) $(\frac{1}{2}{)}^m=\frac{1}{32}$

b) $\frac{343}{125}=(\frac{7}{5}{)}^n$

Tim m và n ( m, n thuộc N*) biết ( -7.x^4 . y^m).(-5.x^n.y^3)=35.x^9.y^15

giúp vs. càng nhanh càng tốt

Tính

\(\frac{9^4.8^6}{6^{10}.16^3}\)

cmr: \(3^{n+2}\).\(2^{n+4}\)+\(3^n\)+\(2^n\) chia hết 30

Câu 1 Tìm các số nguyên nsao cho biểu thức sau là số nguyên;

P=\(\frac{2n-1}{n-1}\)

Câu 2 Tìm a,b,c biết;\(\frac{1}{2}a\)=\(\frac{2}{3}b\)=\(\frac{3}{4}c\) và a-b=15

Câu 3; Tìm các giá trị của x,y thỏa mãn ;

\(^{\left|2x-27\right|^{2011}}\)+\(^{\left(3y+10\right)^{2012}}\)=0

(mấy cái gạch này | không có ý gì đâu, mong mọi người giúp, thanks nhìu )

tính

\(S=\left(\dfrac{-1}{7}\right)^0+\left(\dfrac{-1}{7}\right)^1+\left(\dfrac{-1}{7}\right)^2+...+\left(\dfrac{-1}{7}\right)^{2016}\)

2) -12 : (\(\dfrac{3}{4}\) - \(\dfrac{5}{6}\))²

^{s) \(\dfrac{-1}{12}\)} - (\(2\dfrac{5}{8}\) - \(\dfrac{1}{3}\))

t) -1,75 - (\(\dfrac{-1}{9}\) - \(2\dfrac{1}{18}\))

c) (\(\sqrt{\dfrac{1}{9}}\) - 0,5)³ + \(\dfrac{-1}{3}\)

d) (\(\dfrac{1}{2}\) - \(\sqrt{\dfrac{4}{25}}\))² - \(2\dfrac{1}{2}\)

1. Tìm x ; y ; z biết :

a) \(2009-\left|x-2009\right|=x\)

b) \(\left(2x-1\right)^{2008}+\left(y-\dfrac{2}{5}\right)^{2008}+\left|x+y-z\right|=0\)

2. Tìm a,b,c biết :

\(\dfrac{3a-2b}{5}=\dfrac{2c-5a}{3}=\dfrac{5b-3c}{2}\) và a+b+c=-50

Câu 1: Tìm số tụ nhiên n để \(2n^2-n+2⋮2n+1\)

Câu 2: Cho đa thức f(x) thỏa mãn điều kiện:

(x-2013) . f(x) = (x-2014) . f(x-2012)

Chứng minh rằng f(x) có ít nhất 2 nghiệm.

Câu 3: Tìm 2 số tự nhiên x, y sao cho: \(5^x+1=2^y\)

Tìm x, biết:

\(\sqrt{x^2}\cdot\left|x+2\right|=x\)

a) Biết x + y + 1 = 0. Tính giá trị của đa thức:

M= x³+x²y-xy²-y³+x²-y²+2x+2y+3

b) Tính: P(x)=x⁸-1001 x⁷+1001 x⁶- 1001 x⁵+...+1001 x²- 1001 x + 250.

Cho A= 1²+2²+3²+....+10²=385.Tính S=2²+4²+6²+....+20²

Rút gọn phân số \(\dfrac{9^{20}.2^{27}.22^5}{4^8.18^{18}.33^4}\). Ta đc phân số tối giản là \(\dfrac{a}{4}\). a = ?

chứng minh đa thức 3x^2+3x+1 và x^2+x+1 ko có nghiệm

Tìm a, b, c biết ab = -18, bc = 15, ac = -30

Trả lời hộ mình câu này với:

(3x-2)^5=-243

Tính: \(\left(1000-1^3\right).\left(1000-2^3\right).\left(1000-3^3\right)......\left(1000-50^3\right)=..........\)

Tìm giá trị lớn nhất của M = xy biết x+y =4.

Tìm x biết

a.2(x-1)-3(2x+2)-4(2x+3)=16

b. \(3\dfrac{1}{2}:\left|2x-1\right|=\dfrac{21}{22}\)

c.\(\dfrac{2x-y}{5}=\dfrac{3x-2z}{15}\)và x+z=2y

Tìm nghiệm của đa thức: Q(x) = 2x^{2 - 3x}

Tìm giá trị nguyên của x,y sao cho

5y-3x=2xy-11

\(\dfrac{5.4^{15}.9^9+4.3^{20}.8^9}{5.2^{10}.6^{19}-7.2^{29}.27^6}\)

Tìm x biết: \(\left|2x+3\right|=x+2\)

giải giùm mk bài này nha, thanks

Tìm x:

a, x^2-5x=0

b,3^x+2 + 3^x=810

Tính giá trị của đa thức P(x) = x² - 6x + 9 tại x = 3 và tại x = -3

HELP ME!

Giups mik vs nha:

Tìm nghiệm của:

a,A= 5 - 2x

b,B= 6\(^{ }\)x^2 + 9x

c,C= 2x^2 - 50

d,D= 3x^4 + x^2 + 1

e,E= x^2 - 8x + 7

f, F= x^2 + x +2

Thanks

chứng minh pt: \(a^2+b^2⋮21\) thì \(a^2+b^2⋮441\)

Cho đa thức P(x)=mx-3. Xác đinh m biết rằng P(-1)=2.

Cần gấp

Câu 1: Tìm GTLN của biểu thức 1 - (x - 1)²

Câu 2: Tìm nghiêm của đa thức:

a) x² - 5x + 4

b) 2x² + 3x + 1

Tìm x:

|x - 6| + 2x = 10

HELP ME

1)tìm x biết:

a)(x-2)^2=1

b)(2x-1)^3=-8

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d)(x-2)^3=-27

e(2x-3)^2=25

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h)2^x+2^x+3=144

k)81^-2x*27^x=95

Rút gọn

P=\(2^{2016}\)-\(2^{2015}\)+\(2^{2014}\)-...+\(2^2\)-2

bài này mk ko làm đc giúp mk với nhé m.n

5xⁿ⁺² - 3xⁿ +2xⁿ⁺² -4xⁿ + x^{n+2 - x}n =0

Tính S₃₅+S₆₀+S₁₀₀ với S_n=1-2+3-4+...+(-1)^n-1.n

Bài 4:Tính tổng A = (-7) + (- 7)2 + (- 7)3 + ....+( -7)2007 .CMR A chia hết cho 43

Tính B=1+3+\(3^2+3^3+.....+3^{2015}-\frac{3^{2016}}{2}\)

Chứng minh rằng 10^2006+53/9 là một số tự nhiên

Tổng các giá trị x thỏa mãn: \(\left|x\right|=2^{2015}\) và các giá trị của x là bao nhiêu?

\(\dfrac{x}{5}=\dfrac{y}{6}\) va x+y =55

So sánh

\(\left(\frac{9}{11}-0.81\right)^{2005}......\frac{1}{10^{4010}}\)

Tìm x, biết:

(3 - x) + ( 2x + 7) = 2x

tìm n là số tự nhiên để

A=(n+5).(n+6) chia hết cho 6n

1) Tìm nghiệm của đa thức

a) (x - 3 ) ( 4 - 5x )

b) x\(^2\)- 2

c) x\(^2\) + \(\sqrt{3}\)

d) x\(^2\)+ 2x

e) x\(^2\)+ 2x - 3

Tìm \(A=\frac{1}{2}+\left(\frac{1}{2}\right)^2+\left(\frac{1}{2}\right)^3+\left(\frac{1}{2}\right)^4+...+\left(\frac{1}{2}\right)^{99}\)

Giúp mình với! Tối nay mình học rồi! cảm ơn các bạn nhiều!

\(\dfrac{x}{2}=\dfrac{y}{3}=\dfrac{z}{5}\)va X+Y+Z =-90

Tìm x biết:

1+5+9+13+17+....+x=4950 ( x thuộc N*)

cho P(x)=x-2x²+3x⁵+x⁴+x-1

Q(x)=3-2x+4x⁴-2x²-3x⁵-x⁴+4x²

a)sắp xếp theo lũy thừa giảm dần

b)Tính P+Q; P-Q

Tìm x biết (x - 7)^x+1 - (x - 7)^x+11 = 0