Answer:
x = 3 , y = 4
Step-by-step explanation:
5x + y = 19 --------- ( 1 )
=> y = 19 - 5x
7x - 2y = 13 ------------ ( 2 )
Substitute y in ( 2 ) :
7x - 2( 19 - 5x ) = 13
7x - 38 + 10x = 13
17x = 13 + 38
17x = 51
x = 3
Substitute x in ( 1 ) :
5x + y = 19
5( 3 ) + y = 19
15 + y = 19
y = 19 - 15
y = 4
-10m-18 is the awnser for this one
Answer:
20. y = 3·3^x
21. y = (1/3)^x
Step-by-step explanation:
These exponential functions can be written in the form ...
y = a·b^x
where a is the value of y when x=0, and b is the common ratio between terms that have x different by 1.
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20. The ratio is 9/3 = 3; the multiplier is 3 (the value of y when x=0), so the function is ...
y = 3·3^x
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21. The ratio is (1/3)/1 = 1/3; the multiplier is 1, so the function is ...
y = (1/3)^x
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<em>Alternate solution</em>
Each of these can be written in a more compact form:
20: y = 3^(x+1)
21: y = 3^(-x)
Answer:
Option B is correct.
sum of given geometric series is, 255
Step-by-step explanation:
Evaluate the geometric series: 
we can write this as:
Formula for the sum of the geometric series:
for r > 1
where
a is the first term
n is the number of terms
r is the common ratio
In the given series:
common ratio (r) = 2>1, n = 8 and first term(a) = 1
Since,
and so on...
then substitute the given values in [1] we have;
or
Therefore, the sum of given geometric series is, 255
