Answer:
4.12
Step-by-step explanation:
Answer: D
Step-by-step explanation:
There are two pairs of congruent angles.
All you have to do is substitute the y value from the 1st equation into the second equation and solve...
a) y= 2-x
5x + 4y = 5
Substitute (2-x) into the second equation anywhere there is a y...
5x + 4y = 5
5x + 4(2-x) = 5
Now solve
5x + 8 - 4x = 5
5x - 4x + 8 = 5
x + 8 = 5
x = -3
Now that you have a solution for x, substitute -3 into either of the original equations anywhere there is an x then solve for y...
y = 2 - x
y = 2 - (-3)
y = 2+3 = 5
You solved for x and got -3 and solved for y and got 5, so your solution set is
(-3, 5).
Now check it by substituting both numbers into one of the original equations and you should have a true statement if it is correct...
y = 2 - x
5 = 2 - (-3)
5 = 2+3
5 = 5
True statement... it checks!
note* during the check, if the equation would have worked out to something like 2 = 5, then that is a false statement therefore the solution set would be wrong and you'd have to go back and find the mistake.
Answer: 360 mg of the medicine will be detected after 48 hours
Step-by-step explanation:
We would apply the formula for exponential decay which is expressed as
A = P(1 - r)^t
Where
P represents the initial dosage of the medicine.
A represents the final dosage of the medicine after t hours.
t represents the number of hours.
r represents the rate of decay
From the information given
P = 1000 mg
r = 40% = 40/100 = 0.4
The expression becomes
A = 1000(1 - 0.4)^t
A = 1000(0.6)^t
In 48 hours, t = 2
Therefore,
A = 1000(0.6)^2
A = 360
