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2006 AMC 12B Problems/Problem 8

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Problem

The lines x = \frac 14y + a and y = \frac 14x + b intersect at the point (1,2). What is a + b?

\text {(A) } 0 \qquad \text {(B) } \frac 34 \qquad \text {(C) } 1 \qquad \text {(D) } 2 \qquad \text {(E) } \frac 94

Solution

4x-4a=y

4x-4a=\frac{1}{4}x+b

4*1-4a=\frac{1}{4}*1+b=2

a=\frac{1}{2}

b=\frac{7}{4}

a+b=\frac{9}{4} \Rightarrow \text{(E)}

See also

2006 AMC 12B (ProblemsResources)
Preceded by
Problem 7
Followed by
Problem 9
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
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