<span>first, you have to turn (5y-4)^2 into (5y-4)(5y-4).
From there, you would FOIL, or multilpy the 5y by the 5y, which is 25y^2, the multiply the 5y by the -4, which is -20y, then multiply the -4 by the 5y which is -20y, and then multiply the -4 by the -4, which is 16. It would then look like this: 25y^2 - 20y - 20y +16. Then you would add (or in this case, subtract) like terms. You would add -20y and -20y, which is -40y. The end expression would be 25y^2 - 20y +16. Hope this helps!
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Answer:
x = 1/7
Step-by-step explanation:
23x - 15x = x-1
8x = x - 1
8x - x = 1
7x = 1
x = 1/7
Answer:the answer is 45x
Step-by-step explanation:
Answer: 693 years
Step-by-step explanation:
Expression for rate law for first order kinetics is given by:
k = rate constant
t = time taken for decomposition = 1
= Initial amount of the reactant
= amount of the reactant left =
for half life : 
Putting in the values , we get
Thus half life of this isotope, to the nearest year is 693.
