Question

Daca a supra b =2 supra 3 determinati:
c)a supra 7b
d)3a supra 11b
e)a+b supra b
f)a supra a+b
g)a supra b-a
h)3a-b supra b
i)a supra a+2b
Va rog frumos!

Answer 1

a/b = 2/3

c) a/7b = (a/b)/7 = (2/3)/7 = 2/3 x 1/7 = 2/21
d) 3a/11b = 3/11*a/b = 3/11 * 2/3 = 2/11
e) (a+b)/b = a/b+ b/b = 2/3 + 1 = 2/3 + 3/3 = 5/3
f) a/(a+b) = (a/b)/(a/b + b/b) = (2/3)/(2/3 + 1) = (2/3)/(5/3) = 2/3 x 3/5 = 2/5
g) a/(b-a) = (a/b)/(b/b - a/b) = (2/3)/(1 - 2/3) = (2/3)/(3/3-2/3) = (2/3)/(1/3) = 2/3 * 3/1 = 2
h) (3a-b)/b = (3a/b - b/b)/(b/b) = (3*2/3 - 1)/1 = 2-1 = 1
i)a/(a+2b) = (a/b)/(a/b + 2b/b) = (2/3)/(2/3 + 2) = (2/3)/(2/3+6/3) = (2/3)/(8/3) = 2/3 * 3/8 = 2/8 = 1/4