3x - y = 8 how do I solve this linear equation?
1 answer:
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Answer:
Yes the relationship is linear and given by:
(first option of your list)
Step-by-step explanation:
Yes, it is a linear expression. As we did in previous exercises, we calculate the difference between consecutive y values of the table, and write down the answers we get:
-7-(-2) = -7+2 = -5
-12-(-7) = -12 +7 = -5
-17 - (-12) = -17 + 12 = -5
We notice that all of them give "-5"
Now we evaluate the difference between consecutive x-values in a similar fashion:
-5 -(-9) = -5+9 = 4
-1-(-5) = -1+5 = 4
3-(-1) = 3+1 = 4
We see that they all give 4 as the difference.
That means that the rate of change
This means that the slope (rate of change) of the line is "-5/4"
We can now use the general point-slope form to write the equation of the line, using the first pair of the table as our selected point, and using "-5/4" for the slope:
which is the first expression listed among your possible answer choices.
Simon is 13 years old
Let x be Simon's age
Thus 4 years ago his age was (x - 4) and 2 years from now his age is (x + 2)
Hence 5(x - 4) = 3(x + 2)
distributing both sides gives
5x-20 = 3x + 6
subtract 3x from both sides of the equation
5x - 3x - 20 = 6
2x - 20 = 6
add 20 to both sides
2x = 6 + 20 = 26
divide both sides by 2
x = = 13
Simon is 13 years old