I cannot see Zoe's work to explain the error, but the correct method of solving is listed:
x is the number of 30-second ads
y is the number of 60-second ads
x+y=12(60)=720 would be the first equation; this is because while the ads together make 12 minutes, the ad times are in seconds. This means we must multiply 12 by 60.
y=2x is the second equation
Our system is then
x+y=720
y=2x
We will use substitution to solve this. Plug 2x in place of y in the first equation:
x+2x = 720
Combine like terms:
3x = 720
Divide both sides by 3:
3x/3 = 720/3
x = 240
Substitute this value in for x in the second equation:
y=2(240)
y=480
Answer:
Hey the answer is e i think
Step-by-step explanation:
Answer:
C and E
Step-by-step explanation:
Have a great day! THanks!
Answer:
12x - 15 dollars
Step-by-step explanation:
Sunny earns $12 per hour for delivering cakes.
She worked for x hours this week.
Unfortunately, she was charged $15 for a late delivery on Tuesday
She was supposed to earn $12 × x = $12x this week
But she was charged $15 for late delivery on Tuesday
So her net earning this week is; $12x - $15
Answer: The answer is (C).
Step-by-step explanation: The given statement is - "Two matrices are row equivalent if they have the same number of rows". We are to explain whether the statement is true or false.
What are row equivalent matrices? The answer to this question is -
Two matrices are said to be row equivalent if one of the matrices can be obtained from the other by applying a number of elementary row operations. Or, we can say two matrices of same order are row equivalent if they have same row space.
Thus, the correct option is (C).