4/6
= 2/3
As we take total and divide by what we looking for
.
Answer:
an = 12 -7(n-1)
an = 19-7n
Step-by-step explanation:
The explicit formula for an arithmetic sequence is
an = a1 +d(n-1) where a1 is the first term and d is the common difference
a1 =12
We find d by taking the second term and subtracting the first term
d = 5-12
d = -7
an = 12 -7(n-1)
We can simplify this
an = 12 -7n+7
an = 19-7n
Answer:
in this method a variable is expressed in terms of another variable from one equation and it is substituted in remaining equation.
Step-by-step explanation:
solve:x+2y=9 and 3x-y=13.
x+ 2y=9…be the first equation
3x-y=13…be the second equation
from first equation
x=9-2y…be the third equation substituting value of x from third equation in second equation, we get
3(9-2y)-y=13
or, 27-6y-y=13
or, y=2
now,
substituting value of y in third equation, we get,
x=9-2×2
=9-4
=5
the required value of x and y are 5&2
