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I need help with this question... please look at the question on what is asking for you to do and can you put the answer choices in orderI just need 3,8,9,11,12,13,14

I need help with this question... please look at the question on what is asking for-example-1
User Jukzi
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1 Answer

15 votes
15 votes

NO 3


\begin{gathered} 2\log (y+5)=\log 20\text{ -log5} \\ \log (y+5)^2=\log ((20)/(5)) \\ (y+5)^2=4 \\ \text{square root both sides} \\ y+5\text{ =2} \\ y=2-5 \\ y=-3 \\ The\text{ right option is b} \end{gathered}

N0 8


\begin{gathered} \ln \text{ 8 +ln(n-9)=5ln2} \\ \ln ((n-9)*8)=\ln 2^5 \\ \ln (8n-72)=\ln 32 \\ 8n-72=32 \\ 8n\text{ = 32+72} \\ 8n=104 \\ n=(104)/(8) \\ n=13 \\ \text{Therefore the right answer is f} \end{gathered}

No 9


\begin{gathered} 5\ln (2a-1)\text{ =15} \\ \text{Divide both sides by 5} \\ \ln (2a-1)=3 \\ \text{Take the exponential value of both sides} \\ 2a-1=e^3 \\ 2a-1=20.0855 \\ 2a=1+20.0855 \\ 2a=21.0855 \\ \text{Divide both sides by 2} \\ a=(21.0855)/(2) \\ a=10.5428 \\ \text{The right option is }q \end{gathered}

No 11


\begin{gathered} ((1)/(8))^(2-2n)=16 \\ ((1)/(2^3))^(2-2n)=2^4 \\ 2^(-3(2-2n))=2^4 \\ 2^(-6+6n)=2^4 \\ -6+6n\text{ =4} \\ \text{collect like terms} \\ 6n=4+6 \\ 6n\text{ =10} \\ \text{Divide both sides by 6} \\ n=(10)/(6) \\ n=(5)/(3) \\ \text{Therefore the right answer is }j \end{gathered}

No 12


\begin{gathered} -3e^(2m-5)-7=-34 \\ \text{collect like terms} \\ -3e^(2m-5)=-34+7 \\ -3e^(2m-5)=-27 \\ \text{Divide both sides by -3} \\ e^(2m-5)=(-27)/(-3) \\ e^(2m-5)=9 \\ \text{Find the natural logarithm of both sides} \\ 2m-5\text{ =ln9} \\ 2m-5=2.1972 \\ 2m=5+2.1972 \\ 2m=7.1972 \\ \text{divide both sides by 2} \\ m=(7.1972)/(2) \\ m=\text{ 3.5986} \\ \text{Therefore, the right answer is, p} \end{gathered}

N0 13


\begin{gathered} \log _3(p+4)\text{ + }\log _3(p-2)=3 \\ \log _3(p+4)(p-2)\text{ =3} \\ (p+4)(p-2)=3^3 \\ \text{opening up the bracket} \\ p^2-2p+4p-8=27 \\ p^2+2p-8-27=0 \\ p^2+2p-35=0 \\ We\text{ factorize the above equation} \\ p^2+7p-5p-35=0 \\ p(p+7)-5(p+7)=0 \\ (p-5)(p+7)=0 \\ p=+5\text{ or p=-7} \\ \text{Therefore, the right answer is, e} \end{gathered}

No 14


\begin{gathered} \ln k-\ln 14=2 \\ \ln ((k)/(14))\text{ = 2} \\ Take\text{ the exponential of both sides} \\ (k)/(14)=e^2 \\ (k)/(14)=7.38906 \\ \text{crossmultiply} \\ k=14*7.38906 \\ k=103.4468 \\ \text{Therefore the right answer is, u} \end{gathered}

User Lukejanicke
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