Question

the variable used in equation 4x +9 = 21 is​

Answer 1

Variable used in this equation is x.

$\sf \: 4x + 9 = 21 \\ \sf \: 4x = 12 \\ \boxed{ \sf \: x = 3}$

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Answer 2

Answer:

x=3

Step-by-step explanation:

4x + 9 = 21

4x=21-9

4x=12

x=12÷4

x=3

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