X should be 13 not sure about y
Answer:
2x + 4
Step-by-step explanation:
Let R = Ralph's age
and x = Sarah's age
Then Ralph's age in 4 years = R + 4
and Sarah's age in four years = x + 4
Thus, R + 4 = 2(x + 4)
Distribute the 2 R + 4 = 2x + 8
Subtract 4 from each side R = 2x + 4
Ralph's age is 2x + 4.
Answer:
1 and 1/30 gallons
Step-by-step explanation:
First, convert all the fractions to a common denominator. I'm choosing 30.
1/3=10/30 1/5=6/30 1/2=15/30
Now, you can add them together to get 31/30, so a little more than a gallon
Price elasticity is defined as

.
Here, the question has omitted to define variables, so we will ASSUME
p=price
x=variable,
and we're given
p+x^2-160=0
We calculate

by implicit differentiation with respect to p:
1+2x (dx/dp)=0
=>
E(x)=(dx/dp)=-1/(2x)
Therefore the price elasticity at x=65 is
E(65)=1/(2*65) =-1/130 (approximately -0.00769)
B C are parellagrams the other are NOT