D, Because 7/15 + 9/15 is 16/15 + 4/15 =20/15 which equals 1 5/15 which turns into 1 1/3
A, 1/21 + 2/21 = 3/21 and that equals 1/7
C, 3/14+3/12 turns into 3/14+5/14= 10/14 - 8/14= 2/14=1/7
<h2><u>Corect option</u> :</h2>

<h2><u>Answer with steps</u> :</h2>
Quantity of water she needs 
Number of servings she needs = 10
Number of cups of water she will need :



Thus, she needs
of water.
Therefore, the correct option is 
Answer: yes
Step-by-step explanation:
Answer:
(3, 3 )
Step-by-step explanation:
Given the 2 equations
3x - y = 6 → (1)
6x + y = 21 → (2)
Adding the 2 equations term by term will eliminate y, that is
(6x + 3x) + (y - y) = (21 + 6), that is
9x = 27 (divide both sides by 9 )
x = 3
Substitute x = 3 into either (1) or (2) and solve for y
Using (2), then
(6 × 3) + y = 21
18 + y = 21 ( subtract 18 from both sides )
y = 3
Solution is (3, 3 )