Question 665974
Establish variables
x = tens place
y = ones place
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Given
y=2x
x+y=12
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Substitute y into the second equation
x + 2x = 12
3x = 12
{{{highlight(x = 4)}}} as the digit in the tens place.
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Rearranging y=2x as x = {{{y/2}}}, substitute into the second equation
{{{(y/2) + y = 12}}}
Multiply the entire equation by 2 to be rid of the fraction.
y + 2y = 24
3y = 24
{{{highlight(y = 8)}}} as the digit in the ones place.
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The number is {{{highlight(48)}}}
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Check  {{{cartoon(
4 + 8, 12,
(4)(2),8)}}}
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