Answer:
Part 1) 
The value of x is 
Part 2) 
Step-by-step explanation:
Part 1) Simplify the given equation
we have

In the left side, remove the parenthesis and apply the distributive property
Remember that

so


Combine like terms left side

Adds 7x both sides

subtract 15 both sides

Divide by 7 both sides

Part 2) Solve for x.

Apply distributive property both sides

Group terms that contain the same variable

Combine like terms

Answer:
Young boy will grow to height 132 cm in 12 months.
Step-by-step explanation:
Given:
Growing rate = 3.5 cm per month
Current height = 90 cm
Let the number of months be x
Required height = 132 cm
We need to find the number of months required to grow the height till 132 cm.
Hence Number of months required can be calculate by subtracting Required height with Current height and then dividing it with growing rate.
Framing the above statement in equation form we get;

Hence Young boy will grow to height 132 cm in 12 months.
Your answer makes sense. Though I would recommend using a different variable for each dog at the kennel. Like D. But other than that you're good!
Since the x-coordinate does not change, we know immediately that this straight line is a vertical one. It does not have a slope (div. by zero is undefined).
The equation of this vertical line is x=0.
The line has no y-intercept.
A line perpend. to the given line has a slope of 0.