Answer:
x = 6
Step-by-step explanation:
move all terms to the left:
-1.5x+12-(2.5x-12)=0
get rid of parentheses
-1.5x-2.5x+12+12=0
add all the numbers together, and all the variable.
-4x+24=0
move all terms containing x to the left, all other terms to the right
-4x=-24
x=-24/-4 - divide
x=+6
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
Supplementary angles add up to 180°
-> The measure of an angle that is supplementary to a 71° angle is 180° - 71° = 129°
So,
0.2(n - 6) = 2.8
Distribute.
0.2n - 1.2 = 2.8
Add 1.2 to both sides.
0.2n = 4
Divide both sides by .2.
n = 20
Check.
0.2(20 - 6) = 2.8
Simplify inside parentheses.
0.2(14) = 2.8
Multiply.
2.8 = 2.8 This checks.
S = {2.8}
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