# How do you solve 2x-3+4x=21?

Aug 20, 2017

Combine like terms, and solve for the missing variable.

Answer: $x = 4$

#### Explanation:

Simply start out by combining like terms. That includes any variables with coefficients (numbers in front of the letters), and any other terms. In this case, we can combine $2 x$ and $4 x$ to make $6$, while $- 3$ stands alone as the only number on the left side of the equation. Now we have:

$6 x - 3 = 21$

The following step would be to add $3$ to each side to cancel out the $- 3$ and to consolidate the variable.

$6 x = 24$

Now we simply divide by $6$ to get the variable (which in this case is $x$) alone.

$\frac{6}{6} x = \frac{24}{6}$

These numbers divide evenly with each other to create a quotient such as $x = 4$. Therefore, $x = 4$ is our answer. However let's plug $4$ back into the equation to see if both sides check out.

$6 \left(4\right) - 3 = 21$

$6 \left(4\right) = 24$

$24 - 3 = 21$

Does $21 = 21$? Yes! So our verification checks out.

Answer: $4$

Aug 20, 2017

$x = 4$

#### Explanation:

$2 x - 3 + 4 x = 21$

$6 x - 3 = 21$

$6 x = 21 + 3$

$6 x = 24$

$x = \frac{24}{6}$

$x = 4$