Answer:
So the number of total combinations is 35.
Step-by-step explanation:
We know that Ellen must take 4 courses this semester. She has a list of 3 math courses and 4 science courses.
Therefore, she have total 7 courses.
So, we calculate the number of combinations to choose 4 out of 7 courses.
We get:

So the number of total combinations is 35.
Properties of Logs
logb(x/y) = log<span>bx</span> - log<span>by</span>.
therefore
log5 (4/7)= log5 (4)- log5 (7)
<span>Solve log 5 (4) and log 5 (7) with the base change of the logarithm</span>
<span>log 5 4 = log 4 / log 5 </span>
Use the calculator:
<span>
<span>log 5 4 =0.8613531161
</span></span>
log 5 7 = log 7 / log 5
<span>log 5 7 =1.2090619551</span>
<span>log5 (4/7)= log5
(4)- log5 (7)=-0.347708839</span>
Step-by-step explanation:
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-2a - 6
Hope I helped!
~ Zoe