Answer:
Step-by-step explanation:
a ) Let the volume required be v .
v x .8 + 500 x .3 / ( v + 500 ) = .7
.8 v + 150 = .7 v + 350
.1 v = 200
v = 2000 mL
b )
Let the volume of solution A required be v . The volume of solution of B required will be 100 - v
v x .8 + ( 100 - v ) x .3 / 100 = .5
.8 v + 30 - .3 v = 50
.5 v = 20
v = 40 mL
volume of solution B = 60 mL .
c )
It is not possible because 90 % is more than 80 % the concentration of solution A . Any mixture will have concentration less than 80 % .
volume of solution B = 60 mL
Answer:
If AB = CD then 5 • AB = 5 • CD
Step-by-step explanation:
The multiplication properly of equality states that if two items have the same value, then you could swap them out and the equation would stay the same.
The answer is b. Let me know if you need an explanation
4x+2y=10 Equation 1
x-y=13 Equation 2
Solving by substitution method.
Isolate x from equation 2.
x=y+13
Substitute value of x in equation 1
4(y+13)+2y=10
4y+52+2y=10
6y+52=10
6y=-42
y=-7
Now substitute value of y in x=y+13
x=-7+13
x=6
Answer: (6,-7)