Math Help!!?

Question

Express as a single fraction in lowest terms

(3t-y) / (3t) - (7t+6y) / (7t) +1

Answer 1

You have to find a common denominator. The denominators you are working with are 3t, 7t, and 1, so your lowest common denominator would be 21t

(3t-y)/(3t) - (7t+6y)/(7t) + 1
=[(3t-y)/(3t)]*[7/7] - [(7t+6y)/(7t)]*[3/3] + 1*[(21t)/(21t)]
=(21t-7y)/(21t) - (21t+18y)/(21t) + (21t)/(21t)
=[(21t-7y) - (21t+18y) + (21t)]/[(21t)]
=(21t - 7y - 21t - 18y + 21t)/(21t)
=(21t - 25y)/(21t)
=(21t)/(21t) - (25y)/(21t)
= 1 - (25y)/(21t)

Answer 2

(3t-y) / (3t) - (7t+6y) / (7t) +1
= [(3t-y)(7t+1)]/(3t)(7t+1) - (7t+6y)(3t)/(3t)(7t+1)
= [(21t^2 -7ty + 3t - y) - (21t^2 + 18ty)] / (21t^2+3t)
= (3t - 25ty -y) / (21t^2+3t)

Answer 3

(3t-y)/(3t) -(7t+6y)/(7t) +1 ={ 7t(3t-y)-3t(7t+6y)+21t}/(21t)
={21t^2 -7ty -21t^2 -18ty+21t}/(21t)
={-25ty+21t}/(21t) = (-25y+21)/21

Answer 4

(21t - 7y - 21t - 18y + 21t)/(21t) =
(21t - 25y)/(21t)