+0

# x as the subject

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270
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+164

y = 5(x + 2)

to make x the subject do I need to multiply out the brackets first?

thanks

Jan 28, 2018

#1
+1

y = 5(x + 2)

y = 5x + 10   subtract 10 from both sides

y - 10 = 5x    divide both sides by 5

[y - 10] / 5 =x, or:

x = [y - 10] / 5

You could also do this:

y = 5(x + 2)    divide both sides by 5

y/5 = x + 2     subtract 2 from both sides

y/5 - 2 = x, or:

x =y/5 - 2  Note: Even though they look different, but in fact they are exactly the same.

Jan 28, 2018
edited by Guest  Jan 28, 2018
edited by Guest  Jan 28, 2018
edited by Guest  Jan 29, 2018

#1
+1

y = 5(x + 2)

y = 5x + 10   subtract 10 from both sides

y - 10 = 5x    divide both sides by 5

[y - 10] / 5 =x, or:

x = [y - 10] / 5

You could also do this:

y = 5(x + 2)    divide both sides by 5

y/5 = x + 2     subtract 2 from both sides

y/5 - 2 = x, or:

x =y/5 - 2  Note: Even though they look different, but in fact they are exactly the same.

Guest Jan 28, 2018
edited by Guest  Jan 28, 2018
edited by Guest  Jan 28, 2018
edited by Guest  Jan 29, 2018