Perform the operation given that a = {−3, −2, −1, 0, 1, 2, 3}, b = {−4, −2, 0, 2, 4}, and c = {0, 1, 2, 3, 4}. (enter your answe
Ludmilka [50]
A ∩ c={0,1,2,3}
b ∪ (a ∩ c)={-4,-2,0,1,2,3,4}
Let t represent Todd's age now.
.. 4(t -3) -(t -3) = 81 . . . . . . 3 years ago, their differnce in ages was 81.
.. 3t -9 = 81
.. t = (81 +9)/3 = 30
Todd is 30 now.
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You can also work this by considering "ratio units." 3 years ago, the ratio of their ages was 4:1, a difference of 3. That difference corresponds to 81 years, so each "ratio unit" represents 81/3 = 27 years. Todd's age then was 1 ratio unit, 27 years. Now, Todd's age is 30.
91.5 is the perimeter. It's just 5a.
