How do I solve simultaneous equations by substitution?

You can solve simultaneous equations by either substitution or elimination. Say we have the equations:(1) 8y + 6x = 24 and (2) 2y - x = 6SUBSTITUTION METHODFirst, you need to find x in terms of y (or y in terms of x) by rearranging one of the equations. In this case, we'll rearrange equation (2): (2) 2y - x = 20 => (3) x = 2y - 6Next, plug the new expression (3) into the other equation (1): 8y + 6(2y - 6) = 24 => 8y + 12y - 36 = 24 => 20y = 60 => y = 3Then, you can plug the answer to into the other equation (3) to get the value for x: x = 2(3) - 6 = 0So, x = 0 and y = 3Finally, don't forget to check your answer to make sure the numbers make sense! 8(3) + 6(0) = 24 []

Answered by Joshua N. Maths tutor

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