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y = 3x + 7 - Algerbra 1










































A line has equation y = 3x + 7 and pass through point(h,h + 15). Find the value of h.

Comments for y = 3x + 7 - Algerbra 1

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Apr 17, 2012
y = 3x + 7
by: Staff


Question:

A line has equation y = 3x + 7 and pass through point (h, h + 15). Find the value of h.


Answer:

y = 3x + 7


The line representing the equation passes through the data point (h, h + 15).

This mean that x = h and y = h + 15 at that point.

Because of this equivalence, you can substitute “h” for x in the equation, and “h + 15” for y in the equation.

y = 3x + 7


h + 15 = 3h + 7


Now you can solve for “h” directly

Subtract h from each side of the equation

h + 15 - h = 3h + 7 - h

h - h + 15 = 3h - h + 7

0 + 15 = 3h - h + 7

15 = 3h - h + 7

15 = 2h + 7


Subtract 7 from each side of the equation

15 - 7 = 2h + 7 - 7

15 - 7 = 2h + 0

15 - 7 = 2h

8 = 2h


Divide each side of the equation by 2

2h = 8

2h/2 = 8/2

h*(2/2) = 8/2

h*(1) = 8/2

h = 8/2

h = 4


>>> the final answer: h = 4


Check the answer

y = 3x + 7

if x = h and y = h + 15

h + 15 = 3h + 7

if h = 4

4 + 15 = 3*4 + 7

19 = 19, OK → h = 4 is a VALID solution.




Thanks for writing.

Staff
www.solving-math-problems.com



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