<span>
The right answer is C)
<em>Consistent and independent system</em> of two linear equations is a system such that there is only one solution for the system, that is, the two straight lines cross at a point. So we can analyze each case and I have attached some graphs to provided you with examples. Those graphs aren't about the equations but it's about general cases:
<em>A) </em><u><em>Consistent and dependent</em></u><em>. </em>If we divide this given equation by 2 we get the same line. (See Figure 1)
<em>B) </em><u><em>Inconsistent</em></u><em>.</em><em> </em>No solutions. (See Figure 2)
C) <em><u>Consistent and Independent</u>.</em> (See Figure 3)
D) <u><em>Consistent and dependent</em></u>. If we multiply this equation by -1 we get the same line. (See Figure 1)</span>
Answer:

Step-by-step explanation:
Tip: When
,
is also true.
| <em>Original equation</em>
| <em>Use tip</em>
For the first part
5 an hour plus 50
Can you make an equation out of it
Answer:
- Initial amount of the material is 67 kg
- Hal-life is 83 hours
<u>The required equation is:</u>
- m(x) = 67 *
, where m- remaining amount of the radioactive material, x - number of hours
<u>After 5 hours the material remains:</u>
- m(5) = 67 *
= 64.260 (rounded)