Her brother sent C. 490 messages.
In order to find this, we need to set it up as a proportion. Once we have done that, we can cross multiply and solve for the unknown variable.
(4/7) = (280/x) -----> Cross multiply.
4 * x = 7 * 280
4x = 1960
x = 490
Answer: It is consistent as the lines are intersecting lines and it has a unique solution
Step-by-step explanation:
Since we have given two systems of equation :

We need to check whether the system of equations is consistent or inconsistent.
As we know the formula for checking the consistency :

In first equation we have

similarly,
In the second equation we have

So, According to question, we have

Hence, it is consistent as the lines are intersecting lines and it has a unique solution.
Answer:
he would have used about 87 bands for each ball so if you round to the nearest ten yes it is reasonable to say he used 90 bands per ball
The exact number is 121.966019, so if you round to the nearest whole number, the answer is 122.