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Algebra Difficulty 1.6 Junior Find the answer

A line with equation y=2x+b y = 2x + b passes through the point (4,0)(-4, 0). What is the value of bb?

A number or a short expression. Spacing and $ signs are ignored.

Solution

Since the line with equation y=2x+b y = 2x + b passes through the point (4,0)(-4, 0), the coordinates of the point must satisfy the equation of the line. Substituting x=4x = -4 and y=0y = 0 gives 0=2(4)+b0 = 2(-4) + b and so 0=8+b0 = -8 + b which gives b=8b = 8.

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