# Help with questions C1 Surds

Watch
Announcements
#1
Can someone show some step by step solutions to these two questions

0
5 years ago
#2
Full solutions are not to be shared on this forum.

I will get you started on Q7.

3^(2x+1) * 9^x = 27

3^(2x+1) * (3^2)^x = 27

3^(2x+1) * (3^2x)= 27

Can you use the law a^b * a^c = a^ (b+c) now?

Can you therefore solve for x subsequently using simple logarithms?

Peace.
1
5 years ago
#3
You cant use logs its C1
0
5 years ago
#4
(Original post by WhiteGroupMaths)
Full solutions are not to be shared on this forum.

I will get you started on Q7.

3^(2x+1) * 9^x = 27

3^(2x+1) * (3^2)^x = 27

3^(2x+1) * (3^2x)= 27

Can you use the law a^b * a^c = a^ (b+c) now?

Can you therefore solve for x subsequently using simple logarithms?

Peace.
You cant use logs its C1
0
5 years ago
#5
(Original post by bobjon22444)
You cant use logs its C1
Yes you can.

Posted from TSR Mobile
0
5 years ago
#6
(Original post by Andy98)
Yes you can.

Posted from TSR Mobile
Maybe it depends on the exam board. But you don't learn logs until c2.
0
5 years ago
#7
(Original post by Kholmes1)
Maybe it depends on the exam board. But you don't learn logs until c2.
The question is from an edexcel paper. So indices laws should be used not logs. Because for logs a calculator is required
0
5 years ago
#8
Lol I just want to solutions. The answer to both is x=1/2 but I want to know how it got there, stupid books dont give solutions.
0
5 years ago
#9
(Original post by bobjon22444)
The question is from an edexcel paper. So indices laws should be used not logs. Because for logs a calculator is required
Yeah thats what I thought as well. You can't use it in c1. Do you know what paper it is? Exam Solutions is good.
0
5 years ago
#10
(Original post by Kholmes1)
Maybe it depends on the exam board. But you don't learn logs until c2.
(Original post by bobjon22444)
The question is from an edexcel paper. So indices laws should be used not logs. Because for logs a calculator is required
Oh yeah. I forgot they called them indices laws in C1 but it is the same principle

Posted from TSR Mobile
0
5 years ago
#11
(Original post by WhiteGroupMaths)
Full solutions are not to be shared on this forum.

I will get you started on Q7.

3^(2x+1) * 9^x = 27

3^(2x+1) * (3^2)^x = 27

3^(2x+1) * (3^2x)= 27

Can you use the law a^b * a^c = a^ (b+c) now?

Can you therefore solve for x subsequently using simple logarithms?

Peace.
Is the answer for part a, x= 1/2?
0
5 years ago
#12
Its from a pearson book called revisons work book. I cant seem to find the solutions either.
0
5 years ago
#13
These aren't surds...
0
5 years ago
#14
(Original post by zigocarn)
Is the answer for part a, x= 1/2?
Yes but how did you get it. It must be without logs.
0
5 years ago
#15
(Original post by Hydeman)
These aren't surds...
LOL no its index laws.
0
5 years ago
#16
(Original post by bobjon22444)
LOL no its index laws.
Yes, which is why I'm wondering why the thread advertises it as a surd problem...
1
5 years ago
#17
(Original post by bobjon22444)
Yes but how did you get it. It must be without logs.
It's simple.
What you want to do first is make the bases the same for all three values.
Once the bases are the same, you are able to add the powers.
Remember that the power for both sides are equal to each other and this is why you can solve for x.
0
5 years ago
#18
(Original post by bobjon22444)
Yes but how did you get it. It must be without logs.
Make everything be in the form of 3 to the power something. For example 27 would be .

Then use the rule to solve for x

Posted from TSR Mobile
1
5 years ago
#19
(Original post by Andy98)
Make everything be in the form of 3 to the power something. For example 27 would be .

Then use the rule to solve for x

Posted from TSR Mobile
so 3^2x+1*3^2=3^3 then add powers ?
0
5 years ago
#20
(Original post by bobjon22444)
so 3^2x+1*3^2=3^3 then add powers ?

Posted from TSR Mobile
0
X

new posts
Back
to top
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

### Poll

Join the discussion

#### Poll: What factors affect your mental health most right now? Post-lockdown edition

5.73%
Uncertainty around my education (53)
11.25%
Uncertainty around my future career prospects (56)
11.89%
Lack of purpose or motivation (62)
13.16%
Lack of support system (eg. teachers, counsellors, delays in care) (26)
5.52%
Impact lockdown had on physical health (21)
4.46%
Social worries (incl. loneliness/making friends) (49)
10.4%
Financial worries (29)
6.16%
Concern about myself or my loves ones getting/having been ill (19)
4.03%
Exposure to negative news/social media (31)
6.58%
Difficulty accessing real life entertainment (14)
2.97%
Lack of confidence in making big life decisions (46)
9.77%
Worry about missed opportunities during the pandemic (38)
8.07%