A.) 10x + 7.5 (0) =420
10x = 420
420 / 10 = 42
x = 42 > ( 42,0 )
10(0) + 7.5y = 420
7.5y = 420
420 / 7.25 = 56
y = 56 > ( 0,56 )
(42,0) (0,56)
B.) The x intercept means that there was 42 ,minutes spent biking. The y intercept means that there was 56 minutes spent in line skating.
C.) (21 ,28) - (14,37) - (28,18)
<span>(3x - 1)( x + 5)(4x - 3) = 12x^3 + 47x^2 - 62x +15 </span>
<span>(3x^2 –
x + 15x - 5)( 4x – 3 ) = <span>12x^3 + 47x^2 - 62x +15 </span></span>
<span>(3x^2 +
14x - 5)( 4x – 3 ) = <span>12x^3 + 47x^2 - 62x +15 </span></span>
<span>12x^3 –
9x^2 + 56x^2 – 42x – 20x + 15 = <span>12x^3 +
47x^2 - 62x +15 </span></span>
<span>12x^3 –
47x^2 - 62x + 15 = <span>12x^3 + 47x^2 - 62x +15 </span></span>
<span> </span>
R: (-inf, 0]
D: all real #'s
Answer:
Step-by-step explanation:
Assume that the amount needed from the 5% acid is x and that the amount needed from the 6.5% acid is y.
We are given that:
The volume of the final solution is 200 ml
This means that:
x + y = 200
This can be rewritten as:
x = 200 - y .......> equation I
We are also given that:
The concentration of the final solution is 6%
This means that:
5%x + 6.5%y = 6% (x+y)
This can be rewritten as:
0.05 x + 0.065 y = 0.06 (x+y) ............> equation II
Substitute with equation I in equation II and solve for y as follows:
0.05 x + 0.065 y = 0.06 (x+y)
0.05 (200-y) + 0.065 y = 0.06 (200-y+y)
10 - 0.05 y + 0.065 y = 12
0.015y = 12-10 = 2
y = 2/0.015
y = 133.3334 ml
Substitute with the y in equation I to get the x as follows:
x = 200 - y
x = 200 - 133.3334
x = 66.6667 ml
Based on the above calculations:
The amount required from the 5% acid = x = 66.6667 ml
The amount required from the 6.5% acid = y = 133.3334 ml
