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Solve each equation for y (get into slope-intercept/y=mx + b form): a) 10x + 5y = 20 b) 3x - 2y = 10 + 4x

Don't forget to explain how you got the answers.

User Gbianchi
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1 Answer

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Answer:

see below

Explanation:

We want to solve each equation for y, so y must be alone on one side of the equation.

a) 10x + 5y = 20

Subtract 10x from both sides.

5y = 20 - 10x

Place the x term in front to follow y = mx + b form.

5y = -10x + 20

We want to isolate y completely, so divide both sides by 5. On the right side, be sure to divide each component by 5.

5y/5 = -10/5x + 20/5

y = -2x + 4

This equation is in slope-intercept form.

b) 3x - 2y = 10 + 4x

We can see that y is negative in this original equation. Let's add 2y to both sides to make y positive.

3x = 10 + 4x + 2y

Now we want to isolate y, so subtract 4x from both sides.

3x - 4x = 10 + 2y

Simplify.

-x = 10 + 2y

Isolate y further by subtracting 10 from both sides.

-x - 10 = 2y

Again, we want to isolate y completely, so divide both sides by 2. On the left side, be sure to divide each component by 2.

-x/2 - 10/2 = 2y/2

-1/2x - 5 = y

This looks backwards (although it is in slope-intercept form), so let's rearrange it just to make it more clear.

y = -1/2x - 5

This equation is in slope-intercept form.

Hope this helps!

User Mike Rifgin
by
8.1k points

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