solve the equation.\n2x - 3 + 4x = 21\no x = -12\no x = -6\no x = 4\no x = 6

Explanation:

Step1: Combine like - terms

Combine the $x$ terms on the left - hand side of the equation. $2x+4x - 3=21$ becomes $6x - 3=21$.

Step2: Add 3 to both sides

To isolate the term with $x$, add 3 to both sides of the equation. $6x-3 + 3=21 + 3$, which simplifies to $6x=24$.

Step3: Divide both sides by 6

To solve for $x$, divide both sides of the equation by 6. $\frac{6x}{6}=\frac{24}{6}$, so $x = 4$.

Answer:

$x = 4$