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Maths

Solving equations

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Equations with brackets

If an equation has brackets in it, one method of solving it is to multiply out the brackets first, for example:

Solve the equation: 3(b + 2) = 15

  • 3(b + 2) = 15
  • Multiply out the brackets. Remember, everything inside the brackets gets multiplied by 3.
  • 3 × b + 3 × 2 = 15
  • When you have multiplied out the brackets you get: 3b + 6 = 15
  • Next, undo the + 6. In other words, do the inverse and subtract 6 from both sides.
  • 3b + 6 - 6 = 15 - 6
  • So 3b = 9

Therefore, to find out what b is you need to do the inverse of multiplying by 3 which is dividing by 3.

So b = 3

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