I'm sorry no one can answer and where is the question?
Please put in the question and I might be able to help!
A.
7 times number of cats=pay
if pay=49 then
7 times number of cats=49
divide both sides by 7
number of cats=7
da equaton can be
c=number of cats
7c=49
he fed 7 cats
B.
7c=49
divide both sides by 7
equality property of division
(7c)/7=49/7
math fact
(7/7)c=7
1c=7
identity property of division
c=7
identity property of multiplication
7 cats
C. 7 cats
sinR = 
noting that the sin ratio = 
opposite to ∠P is QR and hypotenuse is PQ ( opposite right angle )
Let n be the amount of 80% solution; and 150-n be the amount of 20% solution. Then:
.8n+.2(150-n)=.6(150)
.8n+30-.2n=90
.6n=60
n=100
150-n=50
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