Answer:
-0.5 is not a solution
2 is a solution
Step-by-step explanation:
To check if something is a solution of the equation, you need to substitute the value in place of the variable
15 + 2y = -12 - 4y
15 + 2(-0.5) = -12 - 4(-0.5)
15 - 1 = -12 + 2
14 ≠ -10 ∴ -0.5 is not a solution
5 - 2(3x + 5) = 3 - 10x
5 - 2[3(2) + 5] = 3 - 10(2)
5 - 2(6 + 5) = 3 - 10(2)
5 - 12 - 10 = 3 - 120
-17 = -17 ∴ 2 is a solution
120 grams half life at 45 days would be 60 then half life of 60 in another 45 days (90 total) should be 30 grams
You can convert 2/3 into a fraction that makes adding a lot easier.
Since 3 times 2 is equal to 6, you can multiply the numerator and denominator of 2/3 by 2 to get 4/6.
From there, you add 4/6 + 5/6 to get 9/6.
Since both 9 and 6 are divisible by 3, you can simplify the fraction to 3/2.
Your final answer would be 3/2
Which can also be formatted as 1 1/2 or 1.5