Y=mx+b m- slope b- y-intercept(where the line crosses the y axis)
31=.5(15)+b plug in your values
31=7.5+b simplify
23.5=b subtract 7.5 from both sides and your given b
y=.5x+23.5 plug everything into slope intercept form (y=mx+b)
Answer:
3 years
Step-by-step explanation:
As with many age problems, you can reason it without equations. If Tom is 13 now, 2 years ago he was 11. If the total age of the two cats at that time was 15, then Tim was 15 -11 = 4.
That means Tim is now 4+2 = 6, so will be 9 in 3 years.
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<em>Additional comment</em>
If you want to write equations, there are several ways you can do it. We often like to use variables to represent the current age. We can assign ...
x = Tim's current age; y = Tom's current age.
The sum of their ages 2 years ago was ...
(x -2) +(y -2) = 15
Tom's current age is 13, so we have y=13. Using that in the equation gives ...
x -2 +13 -2 = 15
x = 6 . . . . . . . . . . subtract 9, collect terms
That's Tim's current age, so Tim will be 9 years old in 3 years.
