A)log7(8x-17)=1 b) log3(4x+3)=0 c)4log81(5x-12)=1 - вопрос №551950178171343048151218311 от evgenqj2002 06.06.2020 21:04

Question

Алгебра: A)log7(8x-17)=1 b) log3(4x+3)=0 c)4log81(5x-12)=1 d)log8(3x-1)=1

evgenqj2002 · Answer

1)log7 (8x-17)=1, 8x-17=7ˇ1,8x-17=7, 8x=24,x=3
2)4.log81 (5x-12)=1
log81 (5x-12)=1/4,(5x-12)=(81)ˇ(1/4),(5x-12)=3, 5x=15,x=3
3)log3 (4x+3)=0, 4x+3= 3ˇ0, 4x+3=1,4x=-2,x=-1/2
4)log8 (3x-1)=1, (3x-1)=8ˇ1,3x-1=8, 3x=9, x=3