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

Solve the equation.<br><br>5/7=10/x+2

skelet666 [1.2K]

Answer:

$x=-\frac{70}{9}$

Step-by-step explanation:

Isolate the variable by doing operations to both sides of the equation.

The work is shown below:

$\frac{5}{7} =\frac{10}{x} +2\\\\\frac{5}{7} - 2=\frac{10}{x} +2 - 2\\\\-\frac{9}{7} = \frac{10}{x}\\\\ -\frac{9}{7}*x = \frac{10}{x}*x\\\\ -\frac{9}{7}x = 10\\\\ -\frac{9}{7}x * (-\frac{7}{9})= 10 * (-\frac{7}{9}) \\\\x=-\frac{70}{9}$

6 0

3 years ago

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