For this case we have the following system of equations:

We multiply the first equation by -1:

We have the following equivalent system:

We add the equations:

Equality is not fulfilled, so the system of equations has no solution.
Answer:
Option C
Answer:
The answer is false already got this question wrong though D;
Step-by-step explanation:
Answer:
n = 1
Step-by-step explanation:
Represent the number by n. Then "seven less than twice a number is -5 becomes 2n - 7 = -5
Next we must solve for n. Adding 7 to both sides yields 2n = 2, so that
n = 1
Estimation:
23 --> rounded to 20
71 --> rounded to 70
70 + 20 = 90. I rounded both numbers down so the exact sum must be only a little greater than my estimate.