Question

1.Tính:

a) a^m+1/a^m+2 với a=-1/2

b)a^m/a^2m+1 với a=-1/4,m=3

c)(a+3)^3/(a+3)^4

Giúp mk nhanh với nhé!!!

Answer 1

a) \(\dfrac{a^{m+1}}{a^{m+2}}\)với \(a=\dfrac{-1}{2}\)

Ta có:

\(\dfrac{a^{m+1}}{a^{m+2}}=\dfrac{a^m.a}{a^m.a^2}=\dfrac{-1}{2}:\left(\dfrac{-1}{2}\right)^2=-2\)

b) \(\dfrac{a^m}{a^{2m+1}}\)với \(a=\dfrac{-1}{4};m=3\)

Ta có:

\(\dfrac{a^m}{a^{2m+1}}=\dfrac{a^3}{a^{2.3}.a}=\dfrac{a^3}{a^6.a}=\dfrac{1}{a^3.a}=\dfrac{1}{\left(-\dfrac{1}{4}\right)^3.\left(-\dfrac{1}{4}\right)}=\dfrac{1}{\left(-\dfrac{1}{4}\right)^4}=256\)

c)\(\dfrac{\left(a+3\right)^3}{\left(a+3\right)^4}\)

Ta có:

\(\dfrac{\left(a+3\right)^3}{\left(a+3\right)^4}=\dfrac{\left(a+3\right)^3}{\left(a+3\right)^3.\left(a+3\right)}=\dfrac{1}{a+3}\)

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