Y=2x + 6. ( because 2x is 2 quarters a day and you started with 6
See the attachment.
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Corresponding sides in the triangles MOP and MNQ are
MO and MN,
OP and NQ,
PM and QM.
Ratios of the corresponding sides for similar triangles should be the same.
MQ/MP =MN/MO
MQ/(MQ+QP) = MN/(MN+NO)
5/(5+x) = 6/(6+18/5)
5*(6+18/5)=6(5+x)
30+18 = 30 +6x
18=6x
x=3 =QP
The answer is :
c. (x+1)²=20
To check:
(x+1)²=20 (a+b)²=a²+2ab+b²
x²+2x+1=20
x²+2x=20-1
x²+2x=19
210.69 is the answer.
Sorry for not explaining my work, in a bit of a hurry. I had this question back when i was in school.
Hope this helps & good luck. :)