By solving this problem, I got D.-8.Right?
Answer:
2x - 18
$3,382
Step-by-step explanation:
x = number of dollars gained last month
this month:
twice the amount = 2x
minus $18 = 2x - 18
x = 1,700
2x - 18
2(1700) - 18
3,400 - 18
$3,382
Step-by-step explanation:



The new matrix obtained from a given matrix by interchanging it's rows and columns is called the transposition of matrix. It is denoted by
. Again , Interchange it's rows and columns in order to find ' A '.

Now , LEFT HAND SIDE ( L.H.S )

Here, I refers to identity matrix. A diagonal matrix in which all the elements of leading diagonal are 1 ( unit ) is called unit or identity matrix.
⟼ 
⟼ 
⟼ 
⟼ 
⟼ 
⟼ 
⟼ 
⟼ 
RIGHT HAND SIDE ( R.H.S ) : 0
L.H.S = R.H.S [ Hence , proved ! ]
Hope I helped ! ♡
Have a wonderful day / night ! ツ
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The correct question is
Use the given information to find the exact value of the expression. sin α = 21/29, α lies in quadrant II, and cos β = 15/17, β lies in quadrant I Find sin (α - β).
we know that
sin(α − β<span>) = </span>sin α cos β − cos α sin β
α lies in quadrant II
so
cos α is negative
sin α is positive
β lies in quadrant I
so
cos β is positive
sin β is positive
step 1
find sin β
cos β=15/17
sin² β+cos² β=1-----------> sin² β=1-cos² β----> sin² β=1-(15/17)²
sin² β=1-225/289-----> 64/289
sin β=8/17
step 2
find cos α
sin α = 21/29
cos² α + sin² α=1----> cos² α=1-sin² α---> cos² α=1-(21/29)²---> 1-441/841
cos² α=400/841------> cos α=-20/29 (remember cos α is negative)
step 3
find sin(α − β)
sin α = 21/29 cos α=-20/29
sin β=8/17 cos β=15/17
sin(α − β) = [21/29]*[15/17] − [-20/29*]*[8/17]
sin(α − β) = [315/493] − [-160/493]
sin(α − β) = 475/493
the answer is
sin(α − β) = 475/493