# sovle by substution

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i don't get this whole concept what-so-ever so lets start with problem one y= -3X +5
5 X - 4y = -3

• sovle by substution -

Your first equation tells a value for Y. Substitute that in the second equation.

5x - 4(-3x + 5) = -3
5x + 12x - 20 = -3
17x = 20 - 3
17x = 17
x = 1

Now substitute 1 for x in the first equation to find a value for y.

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