If she spent $42.15 on dinner it does not matter that this is half.
The equation should be: x-42.15

20
I hope that this is the answer that you are looking for.
Starches help give you an extra boost of energy during your workout. Starches, as well as sugars, eventually break down into glucose -- your body's main fuel source.
Explanation:
When you eat starchy foods, you'll have a supported energy level over a period of numerous hours. This is separate from sugars, which are simple polysaccharides that give you a quick surge of energy but do blank to keep your energy levels running.
Answer:
Myelination.
Explanation:
Brain acts as one of the most important organ of the body that helps in receiving the stimuli and interpret the information in the form of signal. Two main types of neuron are myelinated neuron and unmyelinated neuron.
The myelinated neuron increases the conductivity of the impulse. The myelinated neurons are much more active than the unmyelinated neuron. In case of the quick thinking and instant actions, the myelinated neurons play an important role.
Thus, the answer is myelination.