Let A = {1, 2, 8} and B = {2, 7}.
P ( A ∪ B ) = {1, 2, 7, 8}
= 4/10
= 0.4
Answer: 0.4
X=6y
sum of their reciprocals
(1/x)+(1/y)=7
x=6y
1/6y+1/y=7
1/6y+6/6y=7
7/6y=7
times both sides by 6y
7=42y
divide both sides by 42
1/6=y
x=6y
x=6(1/6)
x=6/6
x=1
the numbers are 1 and 1/6
Answer:
the cost for each gallon is 2.59
Step-by-step explanation:
x + y = 3.36 --> the boys are splitting $3.36
x = 3y - .12 --> one boy received $.12 less than 3 times as much as the other
--> substitute the second equation for the x in the first equation
(3y - .12) + y = 3.36 --> combine like terms
4y - .12 = 3.36 --> add .12 to both sides of the equation
4y = 3.48 --> divide both sides by 4
y = .87
the other boy gets $0.87
substitute into x = 3y - 12
x = 3(.87) - .12
x = 2.61 - .12
x = 2.49
the first boy gets $2.49
Because the discriminant is less than zero, there are no real solutions in the equation.
