515,918 views
33 votes
33 votes
Y=3x+14
2x-3y=-14
Substitution method

User Andreas Vogl
by
2.7k points

2 Answers

20 votes
20 votes
X=-8






I know it’s that so it’s does not need a explanation
User Dnomyar
by
3.6k points
11 votes
11 votes

Answer:

x = -8

Explanation:

y = 3x + 14

2x - 3y = -14

So, what is the substitution? Y of course, this is because y is equal to 3x + 14.

2x - 3 (3x + 14) = -14

Multiply 3 with the numbers in the parentheses.

2x - 9x + 42 = -14

So you maybe be wondering why it is a negative 7 instead of subtracting 9 with 2. Using PEMDAS, we always read from left to right. So it is basically 2 -9 and you get -7.

-7x + 42 = -14

Then subtract 42 from both sides.

-7x + 42 - 42 = -14 - 42

Simplify

-7x = -56

Divide 7 by both sides.

-7x / 7 = -56 / 7

x = -8

And you might ask, why we get x instead afterwards. This is because both -7 and 7 cancel each other out leaving us with x.

User MatthewSot
by
2.5k points
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