Answer:

Step-by-step explanation:
Given the expression 
According to the law of logarithm;
loga + log b = log(ab) and log a - log b = log(a/b)
The given expression becomes;

![\begin{array}{rrrrr} 10x&-&18y&=&2\\ -5x&+&9y&=&-1 \end{array}~\hfill \implies ~\hfill \stackrel{\textit{second equation }\times 2}{ \begin{array}{rrrrr} 10x&-&18y&=&2\\ 2(-5x&+&9y&)=&2(-1) \end{array}} \\\\[-0.35em] ~\dotfill\\\\ \begin{array}{rrrrr} 10x&-&18y&=&2\\ -10x&+&18y&=&-2\\\cline{1-5} 0&+&0&=&0 \end{array}\qquad \impliedby \textit{another way of saying \underline{infinite solutions}}](https://tex.z-dn.net/?f=%5Cbegin%7Barray%7D%7Brrrrr%7D%2010x%26-%2618y%26%3D%262%5C%5C%20-5x%26%2B%269y%26%3D%26-1%20%5Cend%7Barray%7D~%5Chfill%20%5Cimplies%20~%5Chfill%20%5Cstackrel%7B%5Ctextit%7Bsecond%20equation%20%7D%5Ctimes%202%7D%7B%20%5Cbegin%7Barray%7D%7Brrrrr%7D%2010x%26-%2618y%26%3D%262%5C%5C%202%28-5x%26%2B%269y%26%29%3D%262%28-1%29%20%5Cend%7Barray%7D%7D%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill%5C%5C%5C%5C%20%5Cbegin%7Barray%7D%7Brrrrr%7D%2010x%26-%2618y%26%3D%262%5C%5C%20-10x%26%2B%2618y%26%3D%26-2%5C%5C%5Ccline%7B1-5%7D%200%26%2B%260%26%3D%260%20%5Cend%7Barray%7D%5Cqquad%20%5Cimpliedby%20%5Ctextit%7Banother%20way%20of%20saying%20%5Cunderline%7Binfinite%20solutions%7D%7D)
if we were to solve both equations for "y", we'd get

notice, the 1st equation is really the 2nd in disguise, since both lines are just pancaked on top of each other, every point in the lines is a solution or an intersection, and since both go to infinity, well, there you have it.
Answer:
The equation is 1/2 x + 8 = 15 ⇒ answer A
Step-by-step explanation:
* Lets explain how to solve the question
- Grace and her dad are planning to attend the state fair
- The price of an adult ticket is $15
- The price of the adult ticket is one half the price of the student ticket
plus $8
- Assume that the price of the student ticket is x
∵ The price of the student ticket is x
∵ The price of the adult ticket is half the price of the student ticket
x plus 8
- lets multiply half by x and then add the result by 8
∴ The price of the adult ticket = 1/2 x + 8
∵ The price of the adult ticket is $15
- Equate the expression of the price of the adult ticket by the price of
the adult ticket
∴ 1/2 x + 8 = 15
* The equation to determine how much Grace will pay for a student
ticket is 1/2 x + 8 = 15
∴ The answer is choice A
Hi there!
Since angles 3 and 7 are corresponding angles, they are also congruent. This means that angle 3 is equal to angle 7. Therefore, the correct answer is C, 120 degrees.