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25 votes
25 votes
If a+b=12 and a-b=6 find the value of ab

User Wiifm
by
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1 Answer

10 votes
10 votes

Answer:

ab = 27

Explanation:

Hello!

First, let's find the values of a and b.

Solve for a in both equations:

  • a + b = 12; a = 12 - b
  • a - b = 6; a = 6 + b

12 - b and 6 + b are equivalent, as they are both equal to a, so solve for b.

Solve for b

  • 12 - b = 6 + b
  • 6 - b = b
  • 6 = 2b
  • 3 = b

The value of b is 3. We can find a by substituting 3 for b in any of the original equations.

Solve for a

  • a + b = 12; b = 3
  • a + 3 = 12
  • a = 9

The value of a is 9.

We can find ab by substituting the values that we found.

Solve for ab

  • ab; a = 9, b = 3
  • (9)(3)
  • 27

ab is 27.

User Iamkhush
by
3.3k points