Sec a - tan a/cosec a + cot a= cosec a- cot a/ sec a + tan a

See proof below

Step-by-step explanation:

sin a + cos a/sec a+ cosec a= sin a* cos a

(sina+cosa)/(sec a + cosec a)

In trigonometry identity

seca = 1/cos a

cosec a = 1/sin a

Substituted into the given expression

= sina + cosa/(1/cosa+1/sina)

Find the LCM

= sina + cosa /(sina+cosa/sinacosa)

= (sina+cosa) * sinacosa/(sina + cosa)

= sinacosa (RHS)

This shows that the equation is true

step-by-step explanation:

10.50 + taxes which added up to 11.50

7 weeks

step-by-step explanation:

convert each fraction to the least common multiple of 20, so 3/4 = 15/20 & 1/10 = 2/20, then divide 15 by 2 and you get a little over 7, so the food will last 7 weeks.