Question

If x - 15 = 30, what is the value of 2(x + 5)?

Answer 1

Answer:

  100

Step-by-step explanation:

When ...

  x -15 = 30

we can find the value of x by adding 15 to both sides of the equation:

  x = 45

To find the value of 2(x +5), we can substitute 45 for x:

  2(x +5) = 2(45 +5) = 2(50)

  2(x +5) = 100

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Alternate solution

Adding 20 to both sides of the first equation gives the value of x+5.

  (x -15) +20 = (30) +20

  x +5 = 50

The second expression is double this value:

  2(x +5) = 2(50) = 100