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re-arrange the equation to make the speficied variable the subject

(5k − 7t)/11r = 9s, for t

I tried doing this but got the answer wrong can someone please explain how to get to the answer which is t = (5k − 99rs)/7

thanks
Reply 1
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Mr. Ee
2
Original post by lydiafoof
(5k − 7t)/11r = 9s, for t

I tried doing this but got the answer wrong can someone please explain how to get to the answer which is t = (5k − 99rs)/7

thanks


(5k-7t) / 11r = 9s

Start by multiplying both sides by (11r)
(5k-7t) = 99rs

then take away 5k from both sides
-7t = 99rs - 5k

next divide both sides by -7
t = (99rs - 5k) / -7

multiply the fraction by -1
t = (-99rs + 5k) / 7

and re-arrange to get it like the answer
t = (5k-99rs) / 7
Reply 2
Avatar for lydiafoof
lydiafoof
OP
7
Original post by Mr. Ee
(5k-7t) / 11r = 9s

Start by multiplying both sides by (11r)
(5k-7t) = 99rs

then take away 5k from both sides
-7t = 99rs - 5k

next divide both sides by -7
t = (99rs - 5k) / -7

multiply the fraction by -1
t = (-99rs + 5k) / 7

and re-arrange to get it like the answer
t = (5k-99rs) / 7


Thank you, but why do I mutiply the fraction by -1?
Reply 3
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Mr. Ee
2
Original post by lydiafoof
Thank you, but why do I mutiply the fraction by -1?


to move the minus sign from the bottom of the fraction to the top of the fraction (its actually multiplied by -1/-1), to put it in the form the question wants to

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