Sorry I'm quite bad at maths, but wanted to find out

a) 4^(x - 1) + 0.5 = (3/4).2^x

and

b) 4/(x - 6) > 5

thanks

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- April 12th 2010, 11:22 AManindyog[SOLVED] Checking Inequalities
Sorry I'm quite bad at maths, but wanted to find out

a) 4^(x - 1) + 0.5 = (3/4).2^x

and

b) 4/(x - 6) > 5

thanks - April 12th 2010, 11:31 AMe^(i*pi)
The first one is an equation, not an inequality. Remember that for real x and positive a:

b) First things first:

Since the right hand side is positive then it follows that the left hand side must also be positive, this sets a lower bound of and we do not need to worry about the direction of the inequality changing

This gives and you can solve for x in the normal way.

- April 12th 2010, 12:12 PMSoroban
Hello, anindyog!

Quote:

Multiply by 4: .

Factor: .

Therefore: .

- April 12th 2010, 02:14 PManindyog
Thanks alot! However how do you get to 4^x from 4^(x-1) after multiplying it by 4?

- April 12th 2010, 10:53 PMmr fantastic