Think about it this way, what is 5x3??? 15 right. Ok then what is 5x30???? 150. So the store should sell each soccer ball for $5 each:)
Answer: If you mean the math definiton then a quantity or parameter that does not change its value whatever the value of the variables, under a given set of conditions.
Answer:

Step-by-step explanation:
y′′ + 4y′ − 21y = 0
The auxiliary equation is given by
m² + 4m - 21 = 0
We solve this using the quadratic formula. So

So, the solution of the equation is

where m₁ = 3 and m₂ = -7.
So,

Also,

Since y(1) = 1 and y'(1) = 0, we substitute them into the equations above. So,


Substituting A into (1) above, we have

Substituting B into A, we have

Substituting A and B into y, we have

So the solution to the differential equation is

The y value should be -128