Question

The line that is perpendicular to y=-x and passes through the point (2,4) is y=x+ ___?

A. -2
B. 2
C. -4
D. -1
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Answer 1

B. 2

Explanation:

1) all the perpendicular lines are: y=x+C, where C - number;

2) in order to calculate C: to substitute (2;4) into the equation y=x+C:

4=2+C; ⇒ C=2;

3) finally, the required equation is: y=x+2.

The answer is B. 2.