Let t represent Todd's age now.
.. 4(t -3) -(t -3) = 81 . . . . . . 3 years ago, their differnce in ages was 81.
.. 3t -9 = 81
.. t = (81 +9)/3 = 30

Todd is 30 now.

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You can also work this by considering "ratio units." 3 years ago, the ratio of their ages was 4:1, a difference of 3. That difference corresponds to 81 years, so each "ratio unit" represents 81/3 = 27 years. Todd's age then was 1 ratio unit, 27 years. Now, Todd's age is 30.

8 0

3 years ago

Fine the equation, in standard form, of the line passing through the points (3,-4) and (5,1)

Talja [164]

The point-slope form:

$y-y_1=m(x-x_1)\\\\m=\dfrac{y_2-y_1}{x_2-x_1}$

We have the points (3, -4) and (5, 1). Substitute:

$m=\dfrac{1-(-4)}{5-3}=\dfrac{5}{2}\\\\y-(-4)=\dfrac{5}{2}(x-3)$

The standard form: $Ax+By=C$

$y+4=\dfrac{5}{2}(x-3)$ <em>multiply both sides by 2</em>

$2y+8=5(x+3)$ <em>use distributive property</em>

$2y+8=5x+15$ <em>subtract 2y from both sides</em>

$8=5x-2y+15$ <em>subtract 15 from both sides</em>

$-7=5x-2y$

<h3>Answer: 5x - 2y = -7</h3>

5 0

3 years ago

A bumper sticker has an area of five 24 ft.² which model correct present the area of the bumper sticker

Elodia [21]

A picture types of the models would be helpful.. but they could be found in a rectangular shape or square such as width=2 and length =12 vise versa or w=4 and length = 6 , etc etc

6 0

3 years ago