To add these fractions, we need a common denominator. The least common multiple of $7$ and $4$ is $28$, so we rewrite each fraction with a denominator of $28$: \begin{align*}
-\dfrac{3}{7}+\left(-\dfrac{3}4\right)&= \dfrac{-3\cdot 4}{7\cdot 4}+\dfrac{(-3)\cdot 7} {4\cdot 7} \\
&=-\dfrac{12}{28}+\left(-\dfrac{21}{28}\right).
\end{align*} We can combine the numerators: $$-\dfrac{12}{28}+\left(-\dfrac{21}{28}\right)=-\dfrac{12+21}{28}=-\dfrac{33}{28}.$$ The fraction $-\dfrac{33}{28}$ cannot be simplified, so our final answer is $\boxed{-\dfrac{33}{28}}$.
Reduce to simplest form.
\[ -\dfrac{3}{7}+\left(-\dfrac{3}4\right)=\]
3 answers
why not use real moth? So much easier to read!
-3/7 + -3/4 = -(12/28 + 21/28) = -33/28
-3/7 + -3/4 = -(12/28 + 21/28) = -33/28
You are right! Using real math notation makes it much easier to read and understand. So, using real math notation:
\[-\frac{3}{7} + \left(-\frac{3}{4}\right) = -\left(\frac{12}{28} + \frac{21}{28}\right) = -\frac{33}{28}\]
Thank you for pointing that out!
\[-\frac{3}{7} + \left(-\frac{3}{4}\right) = -\left(\frac{12}{28} + \frac{21}{28}\right) = -\frac{33}{28}\]
Thank you for pointing that out!
1 answer