Answer:
N+F=42 & F+3N=70 System Solved: Natalie is 14 and Fred is 28
Step-by-step explanation:
Using variables N=natalies age and F=Freds age
N+F=42 ----> N=42-F (take this and plug it into the other equation)
F+3N=70 so F+3(42-F)=70 [simplify] F+126-3F=70 [further simplify]
-2F=-56 [divide -56 by -2] F=28 [then plug this number into the orig. equation]
So N+28=42 or N=14.
Answer:
(9, 9)
Step-by-step explanation:
midpoint of (-4,15) and (22,3)
65 x 11 I have 2m and a few other people that are not interested to see if they can easily get the best of their time and will
X= 22.5 get the x by itself by dividing by 2
Answer:
y = 3sin2t/2 - 3cos2t/4t + C/t
Step-by-step explanation:
The differential equation y' + 1/t y = 3 cos(2t) is a first order differential equation in the form y'+p(t)y = q(t) with integrating factor I = e^∫p(t)dt
Comparing the standard form with the given differential equation.
p(t) = 1/t and q(t) = 3cos(2t)
I = e^∫1/tdt
I = e^ln(t)
I = t
The general solution for first a first order DE is expressed as;
y×I = ∫q(t)Idt + C where I is the integrating factor and C is the constant of integration.
yt = ∫t(3cos2t)dt
yt = 3∫t(cos2t)dt ...... 1
Integrating ∫t(cos2t)dt using integration by part.
Let u = t, dv = cos2tdt
du/dt = 1; du = dt
v = ∫(cos2t)dt
v = sin2t/2
∫t(cos2t)dt = t(sin2t/2) + ∫(sin2t)/2dt
= tsin2t/2 - cos2t/4 ..... 2
Substituting equation 2 into 1
yt = 3(tsin2t/2 - cos2t/4) + C
Divide through by t
y = 3sin2t/2 - 3cos2t/4t + C/t
Hence the general solution to the ODE is y = 3sin2t/2 - 3cos2t/4t + C/t
