Yvette = 100-7x
Isandro = 0+3x
0+3x = 100 - 7x
0+3x+7x = 100 - 7x +7x
10x = 100
x = 10
So on the 10th time they have the same number, which is 30.
Answer:
a) $0.97
b) $0.16
c) $24.30
Step-by-step explanation:
$0.09 per kilowatt hour = $0.09/kWh
6h/day 30 days = 180h
a) 60W*180h = 10800 Wh = 10.8kWh
10.8kWh * $0.09/kWh = $0.97
b) P = V*I
V = 120V
I = 80mA = 80/1000 = 0.08A
P = 120*0.08 = 9.6W
9.6W*180h = 1728 Wh = 1.728kWh
1.728kWh * $0.09/kWh = $0.16
c) 1500W*180h = 270000 Wh = 270kWh
270kWh * $0.09/kWh = $24.30
We have been given an expression 
. We have been given steps how Chris tried to solve the given expression. We are asked to choose the correct option about Chris's work.
Let us simplify our given expression.
Using exponent property, 
, we cab rewrite our given expression as:
Now we will use exponent property 
to further simplify our expression.
Therefore, Chris made mistake in step 2.
What you do is you distribute the 5.
So your answer would be 5x+15
