Question

a' (x+5) ^3=-64

b, (2x-3) ^2 = 9

c, M = 8^10+ 4^10 / 8^4+ 4^11

Answer 1

a) 

\(\left(x+5\right)^3=-64=\left(-4\right)^3\)

=> x + 5 = -4

=> x = -9

b)

\(\left(2x-3\right)^2=9=\left(\pm3\right)^2\)

+) 2x - 3 = 3

2x = 6

x = 3

+) 2x - 3 = -3

2x = 0

x = 0

Answer 2

c)

\(M=\frac{8^{10}+4^{10}}{8^4+4^{11}}\)

\(M=\frac{2^{30}+2^{20}}{2^{12}+2^{22}}\)

\(M=\frac{2^{20}\left(2^{10}+1\right)}{2^{12}\left(1+2^{10}\right)}\)

\(M=\frac{2^{12}\cdot2^8}{2^{12}}\)

\(M=2^8=256\)

Answer 3

a) ( x + 5 )³ = -64 

<=> ( x + 5 )³ = ( -4 )³

=> x + 5 = -4 

<=> x = ( -4 ) - 5 

<=> x = (-4) + (-5) 

<=> x = - 9

Vậy x = -9

b) (2x - 3 )² = 9 

<=> ( 2x - 3 )² = 3² hoặc (-3)²

=> 2x - 3 = 3 hoặc 2x - 3 = -3

<=> 2x = 3 + 3 hoặc 2x = (-3) + 3 

<=> 2x = 6 hoặc 2x = 0

<=> x = 6 : 2 hoặc x = 0 : 2 

<=> x = 3 hoặc x = 0

Vậy x € { 3 ; 0 }  

Answer 4

a)(x+5)^3=-64

(x+5)^3=(-4)^3

x+5=-4

x=-9

b)(2x-3)^2=9

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

2x-3=3

2x=6

x=3

Answer 5

a) ( x + 5 )³ = -64 

<=> ( x + 5 )³ = ( -4 )³

=> x + 5 = -4 

<=> x = ( -4 ) - 5 

<=> x = (-4) + (-5) 

=> x = - 9

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