Respuesta :
Answer:
1. First equation is option B
2. Second equation is option C
3. Third equation is option E
4. Fourth equation no best option.
explanation:
Check the attachment for solution


Following are the calculation to the differential equation:
For point 1)
[tex]y'' + 8 y' + 15 y = 0\\[/tex]
B
[tex]Y = e^{-3x}[/tex] be the solution of this equation
[tex]Y' = -3 e^{-3x}\\\\ y''= 9 e^{-3x} \\\\\therefore \\\\y'' +8y' + 15 y= 9e^{-3x} + 8(-3e^{-3x})+ 15 e^{-3x} \\\\e^{-3x}( 9-24+15)=0[/tex]
For point 2)
[tex]y'' + y = 0[/tex]
C
[tex]y = \sin x[/tex] be the solution of above equation
[tex]y'= -\cos x \\\\y''= -\sin x = -y \\\\y''+y=0\\\\[/tex]
For point 3)
[tex]y' = 5 y[/tex]
[tex]y'=e^{5x}[/tex] be the solution of equation 3
[tex]y'= 5 e^{5y}= 5y =y'=5y[/tex]
For point 4)
[tex]2x^2 y'' + 3xy' = y[/tex]
Let [tex]y=\sqrt{x}[/tex] be the solution of equation (4)
[tex]y'=\frac{1}{2 \sqrt{x} }\\\\y''=- \frac{1}{2} \times \frac{1}{2} \times {x^{- \frac{3}{2}}} ==- \frac{1}{4} \times {x^{- \frac{3}{2}}} \\\\-2x^2 \times =- \frac{1}{4} {x^{- \frac{3}{2}}}+ 3x \times =- \frac{1}{2 \sqrt{x}}\\\\- \frac{1}{2} {x^{ \frac{1}{2}}}+ \frac{3}{2} x^{\frac{1}{2}} =\sqrt{x} =y\\\\[/tex]
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brainly.com/question/20479450