The answer is 5 (C)
This is because the triangle is an isosceles triangle meaning that both MN and ML are the same length and "5" would make them both 15.
Answer:

Step-by-step explanation:
y=mx+c
where m is the gradient and c is the y-intercept of the line
Let's find the gradient of the line first.

Using the above formula,

Subst. the gradient into m:

Now, find the value of c by substituting a coordinate into the above equation.
when x=-1, y=3,

Therefore the equation of the line is

Do one hundred and twenty nine divided by three and you will get your answer
3. 5x+2y=-19
10x-7y=-16
10x+4y=-38
10x-7y=-16
11y=-22
Y=-2
10x+4c-2=-38
X=-3
4. 10x-4y=20
2x+7y=43
10x-4y=20
10x+35y=215
-39y=-195
Y=5
10x-4x5=20
X=4
Hope this helped :)
You would have to divide 7.47 with 3 which would get you 2.49..you would double that and your answer would be 4.98.