Answer:
a) 8/19 chance
b) 7/19 chance (I'm not 100% sure)
Step-by-step explanation:
A) since there are 8 prime numbers from 1-19 we can say that the probability is 8 over 19 or 8/19
Answer:
Sister = 15 years old
Brother = 12 years old
Step-by-step explanation:
Right now, if the brother is B years old and the sister is S years old, B = (4/5)S because the ratio from brother to sister is 4:5, so if one unit is X, B = 4X and S = 5X
Three years ago, the brother was B-3 years old and the sister was S-3 years old. Keeping one unit as X, we have
B = 3X
S = 4X
B-3 = (3/4)(S-3)
Therefore, we have a system of equations
B = (4/5)S
B-3 = (3/4)(S-3)
Substitute (4/5)S for B into the second equation to only have one variable
(4/5)S - 3 = (3/4)(S-3)
(4/5)S - 3 = (3/4)S - 9/4
add 3 to both sides and subtract (3/4)S from both sides to isolate the variable and its coefficient
(1/20)S = 3/4
multiply both sides by 20 to isolate the S
S = 15
B = (4/5)S = 12
Answer:
450/3
Step-by-step explanation:
Answer:
2y = -x + 7
Step-by-step explanation:
y = -1/2x + 7/2 (Multiply by 2)
2y = -x + 7
Commonly the horizontal axis represent the x-axis. So, you need the point that means x = 3 (positive 3), so, it is the point A.