Question

EX 31 si 32 subpunctele B,C de la ambele exercitii multumesc!

Answer 1

Răspuns:

Explicație pas cu pas:

31

b) (1/7)^x==2/49=(1/7)² ⇒x=2

c)(3/2)^x=225/100=9/4=(3/2)² ⇒x=2

32

b)(1/9)^(x+5)=(1/9)^10 ⇒x+5=10 x=5

c)(3/7)^x:(3/7)³=(3/7)² ⇒x-3=2 x=5

Answer 2

31b.

2/98=1/49=(1/7)²

(1/7)ⁿ=(1/7)², n=2

31c.

225/100=15²/(25×4)=9/4=(3/2)²

(3/2)ⁿ=(3/2)², n=2

32b.

2/18=1/9

(1/9)ⁿ (1/9)⁵=(1/9)¹⁰

(1/9)ⁿ+⁵=(1/9)¹⁰

n+5=10

n=5

32c.

6/14=3/7

15/35=5×3/(7×5)=3/7

(3/7)ⁿ:(3/7)³=(3/7)²

(3/7)ⁿ-³=(3/7)²

n-3=2

n=5