х - количество 50-рублёвых купюр, у - количество 10-рублёвых купюр.
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6/7*(-0,79)-2,74*6/7=6/7( -0,79-2,74)=6/7*(-3,53)=6/7*(-3 53/100)=6/7*(-353/100)=
= -1059/350= -3 9/350
5+2√240+48=53+2√240 вот так вот должно получится
Ответ:
а) х = 1/4 = 0,25; б) х = 4; в) х1 = -3; х2 = 8
Объяснение:
а) 1/х + 5х/(х + 1) = 5
ОДЗ: х ≠0; х ≠ -1
х + 1 + 5х² = 5х² + 5х
4х = 1
х = 1/4
б) (3х² - 48)/(х + 4) = 0
ОДЗ: х ≠ -4
3х² - 48 = 0
х² = 16
х1 = -4 (не подходит из-за ОДЗ
х2 = 4
в) 10/(х - 3) - 8/х = 1
ОДЗ: х ≠ 3; х ≠ 0
10х - 8х + 24 = х² - 3х
х² - 5х - 24 = 0
D = 5² - 4· (-24) = 121
√D= 11
х1 = (5 - 11)/2 = -3
х2 = (5 + 11)/2 = 8