Question 675896
x = one angle
y = other angle
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x = 42 + 3y
x+y = 90
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substitute x into the second equation
42+3y + y = 90
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combine like terms
42 + 4y = 90
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isolate y
4y = 90 - 42
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4y = 48
divide both sides by 4
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{{{highlight_green(y = 12)}}}degrees
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x = 42 + 3y = 42 + 3(12) = 42 + 36 = {{{highlight_green(x=78)}}} degrees
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