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2 years ago

Find the value of y when x equals 4, -3x+9y=-57

Mathematics

2 answers:

Ivenika [448]2 years ago

4 0

-12 + 9y = -57

add 12 to both sides, 9y = -45

divide 9 from both sides to isolate the y

y = -5

adoni [48]2 years ago

3 0

-3(4)+9y=-57
-12+9y=-57
9y=-45
y=-5

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The approximate difference in the half-lives of the isotopes is 66 days.

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The decay of an isotope is represented by the following differential equation:

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The half-life difference between isotope B and isotope A is:

$\Delta t_{1/2} = \left| -\left(\frac{t_{A}}{\ln \frac{m_{A}(t)}{m_{o,A}} } \right)\cdot \ln 2+\left(\frac{t_{B}}{\ln \frac{m_{B}(t)}{m_{o,B}} } \right)\cdot \ln 2\right|$

If $\frac{m_{A}(t)}{m_{o,A}} = \frac{m_{B}(t)}{m_{o,B}} = 0.9$ , $t_{A} = 33\,days$ and $t_{B} = 43\,days$ , the difference in the half-lives of the isotopes is: