Answer:
x = -2
y = 3
Step-by-step explanation:
from above equation we get ,
=》y = 3x + 9
now ,
by second equation,
=》2x + 3y = 5
=》2x + 3 × ( 3x + 9 ) = 5
( since, y = 3x + 9 , by equation 1 )
=》2x + 9x + 27 = 5
=》11x = -22
=》x = -2
putting value of x in equation 1 ;
=》 y = 3x + 9
=》 y = 3 × ( -2 ) + 9
=》 y = -6 + 9
=》 y = 3
From 0.40 to 7.25 is 7.25 - 0.40 or 6.85.
now, if we make 0.40 to be the 100%, what is 6.85 off of it in percentage?
Answer:
2x4 - 50
STEP
2
:
STEP
3
:
Pulling out like terms
3.1 Pull out like factors :
2x4 - 50 = 2 • (x4 - 25)
Trying to factor as a Difference of Squares:
3.2 Factoring: x4 - 25
Theory : A difference of two perfect squares, A2 - B2 can be factored into (A+B) • (A-B)
Proof : (A+B) • (A-B) =
A2 - AB + BA - B2 =
A2 - AB + AB - B2 =
A2 - B2
Note : AB = BA is the commutative property of multiplication.
Note : - AB + AB equals zero and is therefore eliminated from the expression.
Check : 25 is the square of 5
Check : x4 is the square of x2
Factorization is : (x2 + 5) • (x2 - 5)
After 6 hours the drug remains is 19.66 mg if the drug decays at a rate of 20 percent per hour.
<h3>What is exponential decay?</h3>
During exponential decay, a quantity falls slowly at first before rapidly decreasing. The exponential decay formula is used to calculate population decline and can also be used to calculate half-life.
We have:
If a doctor prescribes 75 milligrams of a specific drug to her patient how many milligrams of the drug will remain in the patients' bloodstream.
We know the exponential decay can be given as:
D = a(1 - r)ⁿ
a is the starting value and n is the number of hours.
D = 75(1 - 0.20)⁶
D = 19.66 milligrams
Thus, the after 6 hours the drug remains is 19.66 mg if the drug decays at a rate of 20 percent per hour.
Learn more about the exponential decay here:
brainly.com/question/14355665
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Answer:
64 messages
Step-by-step explanation:
first we simplify the question if the cost of 52 messeges is 4.16 what about the no. of messages that cost 5.12
4.16=52
5.12=?
we multiply 5.12 by 52 and divieded 4.16
5.12*52/4.16=64
