Answer:
p(blue or red) = 0.52 = 52%
Step-by-step explanation:
total number of marbles = 7 + 10 + 14 + 19 = 50
number of blue marbles = 7
number of red marbles = 19
number of blue or red marbles = 7 + 19 = 26
p(blue or red) = 26/50
p(blue or red) = 0.52 = 52%
Answer:
-35a
Step-by-step explanation:
Here, you just distribute: -7 * 5a
= -35a
Answer:
the equation should be corrected to fit the data of the problem. With the corrected equation a mass of 0.5 grams remains after 150 years
Step-by-step explanation:
for the mass y( in grams)
y=23* (1/2)^(t/45), t ≥ 0.
the initial mass is at t=0 , then
y= 23 grams → should be 16 grams
half-life from the equation = 45 years → should be 30 years
the correct equation should be
y=16*(1/2)^(t/30), t ≥ 0
then after 150 years → t= 150
y=16*(1/2)^(150/30)= 16*(1/2)^5 = 16/32 = 0.5 grams
then a mass of 0.5 grams remains after 150 years
The solution (x,y) needs to work in both equations. With multiple choice you can do guess and test method. Otherwise you need to combine the two equations into one by substitution or elimination methods.
21. substitution works well here since one equation is y= x+3. you can easily substitute the (x+3) for y in the other equation.
2x + (x+3) = -6
3x + 3 = -6
3x = -9
x = -3
use this in either equation to find y.
y = (-3)+3
solution: (-3,0)
22. these both equal y so they equal each other.
4x - 1 = 3x +6
4x - 3x = 6 + 1
x = 7
use this in either equation to find y
y = 4(7) - 1
y = 28 - 1
y = 27
solution: (7,27)
23. one equation is y = 2x - 3. So substitute (2x -3) for y in the other equation.
4x = 2(2x - 3) + 6
4x = 4x - 6 + 6
4x = 4x
x = x
any solution will work, infinitely many.
24. infinitely many solutions means the two equations are the same equation. Like the previous one they didn't look the same but if you put them both in terms of y...
y= 2x-3
4x = 2y + 6
4x - 6 = 2y
(4x - 6)/2 = y
2x - 3 = y
same equation.
from the image, I can't see all options but A & C do not look like the same equations. It's got to be either B or D.
