Answer:
<em>He bought 6 hotdogs and 2 drinks</em>
Step-by-step explanation:
<u>System of Equations</u>
Kevin and his children went into a restaurant and bought $31.50 worth of hotdogs and drinks. Each hotdog costs $4.50 and each drink costs $2.25.
To solve the system of equations, we'll call the variables:
x = number of hotdogs
y = number of drinks
The first condition yields the equation:
4.50x + 2.25y = 31.50 [1]
It's also known he bought 3 times as many hotdogs as drinks, thus:
x = 3y [2}
Substituting [2] in [1]:
4.50(3y) + 2.25y = 31.50
Operating:
13.5y + 2.25y = 31.50
15.75y = 31.50
y = 31.50/15.75
y = 2
And
x = 3*2 = 6
He bought 6 hotdogs and 2 drinks
Answer:
the rate of change of the area is Ra= 80 mm² per second
Step-by-step explanation:
the area of a rectangle (A) is
A = L * W , L= length and W= width
if the width remains constant the change in the area is only due to the change in length , thus:
ΔA = Δ( L * W ) = W * ΔL , where ΔA represents the change in area and ΔL represents the change in length
ΔA = W ΔL
denoting Δt as the time required to change, and dividing both sides by Δt
ΔA/Δt = W ΔL/Δt
where Ra=ΔA/Δt = rate of change of the area and RL=ΔL/Δt rate of change of the length.
thus
Ra = W * RL
replacing values
Ra = W * RL = 8 mm * 10 mm/second = 80 mm² /second
Really true. just wanting points is not a reason to mess with someone else.
