
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
Given vectors $\overrightarrow {e_{1}} = (-1, 2)$, $\overrightarrow {e_{2}} = (5, -2)$, and vector $\overrightarrow {a} = (-4, 0)$, express vector $\overrightarrow {a}$ in terms of $\overrightarrow {e_{1}}$ and $\overrightarrow {e_{2}}$. The expression for $\overrightarrow {a}$ is \_\_\_\_\_\_.

Present the answer in LaTex format: \boxed{Your answer}
user