Question 210434
From the information given, you can write 2 equations:
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Equation #1: {{{A+B=90}}}
Equation #2: {{{B=3A}}}
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Substitute the expression for B from Equation #2 into Equation #1:
{{{A+3A=90}}}
Solve for A and you are done!
{{{4A=90}}}
{{{highlight(A=22.5)}}}
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Good Luck,
tutor_paul@yahoo.com