The equation of direct variation is,

Substitute the values of <em>y</em> and <em>x</em>.

So, the obtained equation will be <em>y</em>=1.35(x).
Let's check with the values of <em>x</em>.
1) If <em>x</em>=4

2) If <em>x</em>=2

3) If <em>x</em>=-2
The answer is -8
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Explanation:
There are two ways to get this answer
Method 1 will have us plug x = 0 into h(x) to get
h(x) = x^2 - 4
h(0) = 0^2 - 4
h(0) = 0 - 4
h(0) = -4
Then this output is plugged into g(x) to get
g(x) = 2x
g(-4) = 2*(-4)
g(-4) = -8 which is the answer
This works because (g o h)(0) is the same as g(h(0)). Note how h(0) is replaced with -4
So effectively g(h(0)) = -8 which is the same as (g o h)(0) = -8
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The second method involves a bit algebra first
Start with the outer function g(x). Then replace every x with h(x). On the right side, we will replace h(x) with x^2-4 because h(x) = x^2-4
g(x) = 2x
g(x) = 2( x )
g(h(x)) = 2( h(x) ) ... replace every x with h(x)
g(h(x)) = 2( x^2-4 ) ... replace h(x) on the right side with x^2-4
g(h(x)) = 2x^2-8
(g o h)(x) = 2x^2-8
Now plug in x = 0
(g o h)(x) = 2x^2-8
(g o h)(0) = 2(0)^2-8
(g o h)(0) = 2(0)-8
(g o h)(0) = 0-8
(g o h)(0) = -8
Regardless of which method you use, the answer is -8
20 - 21 - 10 + 5x +1= 0
5x = 10
x = 2
<span>4x - 15 = 3 </span>
<span>4x = 3 + 15 </span>
<span>4x = 18 (divide both sides by 4 to get x) </span>
<span>4x/4 = 18/4 </span>
<span>x = 4.5 </span>