10 800 0 to the first problem
<h2>Solving Equations</h2>
To solve linear equations, we must perform inverse operations on both sides of the equal sign to <em>cancel values out</em>.
- If something is being added to x, subtract it from both sides.
- If something is being subtracted from x, add it on both sides.
- Same with multiplication and division. If x is being divided, multiply. If x is being multiplied, divide.
We perform inverse operations to<em> combine like terms</em>. This means to get x to one side and everything else on the other.
<h2>Solving the Questions</h2><h3>Question 1</h3>

Because 7 is being added to x, subtract it from both sides:

Because x is being multiplied by 5, divide both sides by 5:

Therefore.
.
<h3>Question 2</h3>

Here, we can group all the x values on the left side of the equation. Subtract 5x from both sides:

To isolate x, subtract 4 from both sides:

Divide both sides by 2:

Therefore,
.
Answer:
127.17 cm²
Step-by-step explanation:
- Area of a semicircle: 1/2*π*r²
- π (pi) = 3.14
- r (radius) = d (diamater) / 2 => 18/2 = 9 cm
A = 1/2*π*r²
A = 1/2*3.14*9²
A = 1/2*3.14*81
A = 3.14*40.5
A = 127.17 cm²
Therefore, the area of the semicircle is 127.17 cm²
Hope this helps!
The whole school would have 170 students that have a dog
This is equivalent to finding a function g in which

.
We simply reverse the actions of the initial function by adding 81 back and taking the square root. Therefore,

.