The answer is 14 because you have to substitute every answer with x and find which one both are equal to each other because both sides of the triangle are equal it is an equilateral triangle so the angles need to be congruent.
Answer:
y=2x+5
Step-by-step explanation:
To find a linear equation you must find the slope and y intercept to create an equation in y=mx+b form (slope-intercept form)
So slope is = y2-y1 / x2-x1 [2 and 1 are subscripts] so 11-7/3-1 so m=4/2 = 2
Slope = 2, now find b
So using y = mx + b, substitute what you know so 7 = 2(1) + b so b=7-2 = 5
Put it all together y = 2x + 5
You have the following function:

Derivate implictly the previous expression, as follow:

Where you have used that:

Then, the implicit derivative of the given expression is:

Next, solve for y' as follow:

4-9= -5 that is the answer