# Thread: How to make 'T' the subject?

1. ## How to make 'T' the subject?

Hello

Can anyone help with the rearrangement of this formula to make 'T' the subject?

((Tx£1-£1)x58)+((-£1)x(100-58)) = £7.88

Whenever I try I get the wrong answer. I must be pretty stupid as I am sure this is probably quite basic GCSE level maths. Thanks in advance.

Dan Wright

2. ((Tx£1-£1)x58)+((-£1)x(100-58)) = £7.88

I think you may be missing brackets in the first section.. i think you could maybe interpret this a number of ways......

Maybe..

( 58(T£ - £1) ) + (-1£ x 42 ) = £7.88

58T£ - 58£ - 42£ = £7.88

58T£ - 100£ = £7.88

58T£ = £107.88

T£ = £107.88 / 58

T£ = 1.86

3. Thanks for you help Joel. In this formula, 'T' should actually = 1.86. I have taken the formula from my Microsoft Excel spreadsheet and the formula works fine to calculate £7.88 when 'T' = 1.86. Maybe in Excel brackets work slightly differently, I am not sure.

Basically 'T' needs to = 1.86 and is separate from the £1 value.

Any ideas? Thanks.

Dan

4. Simple error with my subtraction Dan. Error fixed

5. Oh yes, thanks very much for your help. Saved me a lot of problems.

Dan