Răspuns :
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
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