# substitution

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solve by the substitution method

3x+5y=21
x=51-9y

• substitution -

substitute x in the eq 3x+5y=21
3(51-9y)+5y=21
153-27y+5y=21
153-22y=21
-22y=21-153
-22y=-132
-22y/-22=-153/-22
y=6

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