Note that c is the hypotenuse of the blue triangle, and that the Pyth. Thm. states that (length of one leg)^2 + (length of the other leg)^2 = (hyp)^2.
Therefore, (hyp)^2 = c^2 = [2sqrt(x^2+3x)]^2 + 3^2, or
= 4(x^2+3x) + 9, or
= 4x^2 + 12x + 9 = (2x+3)^2
Taking the sqrt of both sides, c = plus or minus (2x+3). Eliminate -(2x+3) because the middle term of the square of this would be negative, in conflict with the given +12x.
c=2x+3 is the correct answer.
If it takes 10 machines 10 minutes to make 10 items, I would assume it would take 50 machines 50 minutes to make 50 items. Hope this helps :)
Answer:
a) Here we have:
"In Family A, the youngest child is 7 years younger than the oldest, who is 18"
Let's define:
Y = age of the youngest child.
O = age of the oldest child.
Then we know that:
Y = O - 7
O = 18
Then we can replace the second equation into the first one:
Y = 18 - 7 = 11.
b) Here we have:
"In Family B, the middle child is 5 years older than the youngest child."
Let's define:
Y = age of the youngest child.
M = age of the middle child.
Here we have only one equation:
M = Y + 5.
It's 78π inches so probably d.
