Question

1) tìm x, y

(2x-1).(y+4)=11

2) so sánh C=27⁵ và 234³

Answer 1

=> (2x-1)(y+4) = 1.11  = (-1)(-11)

2x - 1= 1 ; x = 1

y + 4 = 11 ; y = 7

+  2x - 1 = 11 ; x = 6

y + 4 = 1 ; y = -3

+ 2x - 1 = - 1

2x = 0 ; x = 0

y + 4 = -11 ; y = -15

+ 2x - 1 = -11 ; x = -5

y + 4 = -1 ; y = -5

C = (3³)⁵ = 3¹⁵ = 27³ . 3⁶

234³ = 2³ . 3⁶ . 13³ = 3⁶ . (2.13)³ = 3⁶ . 26³

Nên C > 234³

Answer 2

2) 

Ta có  : \(27^5=\left(3^3\right)^5=3^{15}=\left(3^5\right)^3=243^3\)

 

Vì : \(243>234\Rightarrow243^3>234^3\)

Hay \(27^5>234^3\)