WEBVTT
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What is the π¦-intercept of the function three π¦ equals 15π₯ plus eight [18]?
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The π¦-intercept is the place where the function crosses the π¦-axis.
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Another way to say that, is the coordinate of π¦ when π₯ is zero.
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And when a function is written as π¦ equals ππ₯ plus π, the π represents the π¦-intercept.
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Our function is written as three π¦ equals 15π₯ plus 18.
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How can we change our function to be in the format π¦ equals ππ₯ plus π?
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Hereβs the difference.
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In π¦ equals ππ₯ plus π, the π¦ is isolated.
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Thereβs nothing being multiplied by the π¦.
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So letβs isolate our π¦.
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Right now, our π¦ is being multiplied by three.
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To isolate π¦, weβll divide by three on both sides of the equation.
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Three times π¦ divided by three, and then 15π₯ plus 18 divided by three.
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On the left side, our threes cancel out leaving us with π¦.
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On our right side, we need to divide each term by three, which means 15π₯ divided by three plus 18 divided by three.
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15π₯ divided by three equals five π₯.
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18 divided by three equals six.
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Once our function is in this form, π¦ equals ππ₯ plus π, whatever values in the π position is our π¦-intercept.
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For this function, the π¦-intercept equals six.