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If 7(y - 5) = 21, how do I expand the brackets so that I can find the value of y?

This equation has a single term outside the brackets. This term is highlighted in green.

7(y - 5) = 21

When an equation has a single term outside the brackets, we must multiply each term inside the brackets by the term outside the brackets.



In our example, that means that we must multiply the y by 7 and the -5 by 7.

y x 7 -5 x 7 = 21

We can then simplify this:

7y - 35 = 21

Add 35 to both sides of the equation:

7y = 56

y = 8

We have found that y is equal to 8.