Is there supposed to be an attached image for us to see?
She knits 18 squares on Monday.
Then she knits 7 more squares each day:
Tuesday: +7, Wednesday: +7, Thursday: +7 and Friday: +7
18 + 7 * 4 = 18 + 28 = 46
Answer: She has 46 squares on Friday.
Since we will be completing the square we need to isolate the x
y-5 = 2x^2 -4x
now we the coefficient of the x^2 to equal 1 so we take 2 as common factor
y-5 = 2(x^2 -2x)
now we'll make it perfect square by adding 2 to both sides
y-5+2=2(x^2-2x+1)
now simplify and convert the right side to squared expression
y-3 = 2(x-1)^2
now isolate the y
y = 2(x-1)^2 +3 that's it
The answer is -6
(9-15)=-6
(-8+2)=-6
(24-30)=-6
-(-6)+(-6)-(-6)= -6