Answer:
x=25
Step-by-step explanation:
3x-5=2x+20=4x-30
3(25)-5 = 2(25) + 20 = 4(25) - 30
75-5 = 50 + 20 = 100 - 30
70=70=70
Answer:
14.99 hours
Step-by-step explanation:
The formula for half-life is given as,
R/R' = 2ᵃ/ᵇ...................... Equation 1
Where R= Original mass of sodium-24, R' = mass of Sodium-24 after disintegration, a = Total time taken for sodium-24 to disintegrate, b = half-life of sodiun-24.
Given: R = 1 kg, R' = 0.0156 kg, a = 90 hours
Substitute into equation 1 and solve for b
1/(0.0156) = 2⁹⁰/ᵇ
Taking the log of both side
log[1/(0.0156)] = log(2⁹⁰/ᵇ)
log[1/(0.0156)] = 90/b(log2)
90/b = log[1/(0.0156)]/log2
90/b = 6.0023
b = 90/6.0023
b = 14.99 hours
b = 14.99 hours.
Hence the half-life of Sodium-24 is 14.99 hours
I'm assuming that there is another root which should be -SQRT(11)
f(x) = x(x-4)(x+SQRT(11))(x-SQRT(11)
Then
f(x) = x^4 -4x^3 - 11x^2 +44x