Can someone please help me, i don't understand this work.

Check out the diagram below for the filled out table

Equation is y = 1.5x

Box for row one = 330

Box for row two = 1000

Box for row three = 1.5

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Explanation

The point (x,y) = (200,300) is on the blue diagonal line. It indicates that x = 200 grams of fish have y = 300 calories. Divide the two values to get the slope

slope = y/x = 300/200 = 1.5

This trick only works because the line is going through the origin. Otherwise, we'd have to use the slope formula.

The slope of 1.5 is the constant of proportionality. It tells us the equation is y = 1.5x. Whatever x is, multiply by 1.5 to get y.

So if x = 220, then y = 1.5x = 1.5*220 = 330

220 grams of fish have 330 calories. We'll write 330 in the box of the first row of the table.

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We can use this idea in reverse. If we know the calorie count (y), then we can divide by 1.5 to get the number of grams (x).

y = 1.5x

1500 = 1.5x

1.5x = 1500

x = 1500/(1.5)

x = 1000

Therefore, 1000 grams of fish have 1500 calories. We'll write 1000 in the box of the second row.

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The third row of the table is going to follow the same steps as the first row.

y = 1.5x

y = 1.5*1

y = 1.5

One gram of fish produces 1.5 calories

The filled out table is shown below. I've merged the two screenshots you posted into one image, and filled out the boxes.

f(x) is going down by 4

step-by-step explanation:

(its either that or its going left by 4)

step-by-step explanation:

step 1: solve one of the equations for one of the variables. let's solve the first equation for y:

step 2: substitute that equation into the other equation, and solve for x.

step 3: substitute x = 4 x = 4 x=4 into one of the original equations, and solve for y.