What is the solution to this system of equations? y= 3x + 5 y= -x + 3 a// (2.1, 11.3) b// (-2.1, 5.1) c// (-0.5, 3.5) d// (0.5, 2.5)

c

Step-by-step explanation:

Since both equations express y in terms of x we can equate the right sides

3x + 5 = - x + 3 ( add x to both sides )

4x + 5 = 3 ( subtract 5 from both sides )

4x = - 2 ( divide both sides by 4 )

x = - 0.5

substitute x = - 0.5 in either of the 2 equations

using y = - x + 3 then y = 0.5 + 3 = 3.5

solution is (- 0.5, 3.5 ) → c

Dec 10

Step-by-step explanation:

0.25 liter = 250 ml

4 ml * 3 = 12 ml

250/12 = 20.83 days

Nov 20 - Nov 30: 11 days

Dec 1 - Dec 9: 9 days

On December 9, she can still take her 3 doses.

By December 9, she will have taken 12 ml per day for 20 days for a total of 240 ml. She has 10 ml left for Dec 10th.

On Dec 10, she will take 2 doses of 4 ml and 1 dose of 2 ml, and she will finish the medicine.