c = cost per pound of chocolate chips
w = cost per pound of walnuts.
![\bf \stackrel{\textit{3 lbs of "c"}}{3c}+\stackrel{\textit{5 lbs of "w"}}{5w}~~=~~\stackrel{\textit{costs}}{15} \\\\\\ \stackrel{\textit{12 lbs of "c"}}{12c}+\stackrel{\textit{2 lbs of "w"}}{2w}~~=~~\stackrel{\textit{costs}}{33} \end{cases}\qquad \impliedby \textit{let's use elimination} \\\\[-0.35em] ~\dotfill\\\\ \begin{array}{llccccccl} 3c+5w=15&\times (-4)\implies &-12c&+&-20w&=&-60\\ 12c+2w=33&&12c&+&2w&=&33\\ \cline{3-7}\\ &&0&&-18w&=&-27 \end{array}](https://tex.z-dn.net/?f=%5Cbf%20%5Cstackrel%7B%5Ctextit%7B3%20lbs%20of%20%22c%22%7D%7D%7B3c%7D%2B%5Cstackrel%7B%5Ctextit%7B5%20lbs%20of%20%22w%22%7D%7D%7B5w%7D~~%3D~~%5Cstackrel%7B%5Ctextit%7Bcosts%7D%7D%7B15%7D%20%5C%5C%5C%5C%5C%5C%20%5Cstackrel%7B%5Ctextit%7B12%20lbs%20of%20%22c%22%7D%7D%7B12c%7D%2B%5Cstackrel%7B%5Ctextit%7B2%20lbs%20of%20%22w%22%7D%7D%7B2w%7D~~%3D~~%5Cstackrel%7B%5Ctextit%7Bcosts%7D%7D%7B33%7D%20%5Cend%7Bcases%7D%5Cqquad%20%5Cimpliedby%20%5Ctextit%7Blet%27s%20use%20elimination%7D%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill%5C%5C%5C%5C%20%5Cbegin%7Barray%7D%7Bllccccccl%7D%203c%2B5w%3D15%26%5Ctimes%20%28-4%29%5Cimplies%20%26-12c%26%2B%26-20w%26%3D%26-60%5C%5C%2012c%2B2w%3D33%26%2612c%26%2B%262w%26%3D%2633%5C%5C%20%5Ccline%7B3-7%7D%5C%5C%20%26%260%26%26-18w%26%3D%26-27%20%5Cend%7Barray%7D)
Given a quadratic equation 
, we define the discriminant as
The number of real solutions of the equation depend on the sign of 
:
- If
the equation has two solutions - If
the equation has one double solution - If
the equation has no real solutions
In this case, we have
And so this equation has no real solutions.
You are given the X value, replace x with 2 in the first equation to solve for y:
y=2x +3
y = 2(2) +3
y = 4+3
y = 7
Now replace y with 7 and x iwth 2 in the second equation and solve for k:
y = -x +k
7 = -2 +k
Add 2 to both sides:
9 = k
so k = 9
The point is given as k-2, which is 9-2 = 7, which is what y equals in the first equation.
K = 9
X = 5
Y = 6
Simply we just compare the two shapes and we can see that 6 decreases to 4..so we would assume the rest would decrease by 2. If we were not so sure we could simply do a^2 + b^2 = c^2 and fill in the numbers
