Question

Identify the equation in slope intercept from that has a slope of 2 and goes through the point (4, 6).

y=−2x+2

y=2x+14

y=2x+6

y=2x−2

Answer 1

D) y=2x-2

Explanation:

y-y1=m(x-x1)

y-6=2(x-4)

y=2x-8+6

y=2x-2

Answer 2

y = 2x−2

Explanation:

You are given a slope and a point, so you can write the equation using point-slope form:

y -k = m(x -h) . . . . . . a line with slope m through point (h, k)

Putting in the numbers given, you have ...

y -6 = 2(x -4)

y = 2x -8 +6 . . . . eliminate parentheses, add 6

y = 2x -2 . . . . . . . collect terms.

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You know that the slope is the coefficient of x, so the first choice is eliminated right away. Trying the point values in the other equations shows you that they only work for the last choice, as shown above.

• 2·4 +14 = 22 ≠ 6 . . . . second choice doesn't work
• 2·4 +6 = 14 ≠ 6 . . . . . third choice doesn't work
• 2·4 -2 = 6 . . . . . . y = 2x-2 is the equation that works