Answer:
Answer choice C
Step-by-step explanation:
This is the only graph which has a linear equation and starts from 0,0.
X = 5
since we know y= 5 + x , plug this into y in the second equation.
2x + 2 (5 + x) = 30
distribute 2 into the 5 and x
2x + 10 + 2x = 30
combine like terms
4x + 10 = 30
subtract 10 from both sides
4x = 20
divide four by both sides to isolate the variable
x = 5
Answer:
K = 42
Step-by-step explanation:
K/2 = 21
2* k/2 =2*21
k=42
Let x = volume of saline solution A,
y = volume of saline solution B.
We're going to set up two equations.
Firstly, x + y = 6. That gives us y = 6 – x (1)
Second, 0.1x + 0.05y = 0.08•6,
or 0.1x + 0.05y = 0.48 (2)
Substitute (1) into (2):
0.1x + 0.05(6 – x) = 0.48
0.1x + 0.3 – 0.05x = 0.48
0.05x + 0.3 = 0.48
Subtract 0.3 from both sides:
0.05x = 0.18
x = 3.6
Then y = 6 – 3.6 = 2.4
So we have to use 3.6 litres of solution A and 2.4 litres of solution B.