1)кх+3=15
х=-1
тогда
к*(-1)+3=15
-к+3=15
-к=15-3
-к=12
к=-12
2)5х-4у=15
5х=15+4у
х=15+4у\5
Ответ:
(3×7)+(2×4)=29
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б)
b₁ = 16√2
q = -√2/2
bₙ = b₁ * qⁿ⁻¹ = 16√2 * (-√2/2)ⁿ⁻¹
b₅ = 16√2 * (√2/2)⁴ = 16√2 * 1/4 = 4√2
г)
b₁ = -√3/3
q = -√3
bₙ = b₁ * qⁿ⁻¹ = -√3/3 * (-√3)ⁿ⁻¹
b₅ = -√3/3 * (-√3)⁴ = -√3/3 * 9 = -3√3