Answer:
After 120 seconds
Step-by-step explanation:
Here, we want to know the number of seconds after which both spotlights will change colors at the same time again.
Basically, what we want to do here is to
calculate the value with which 30 and 40 have the same multiples or we want to
calculate the lowest common multiple of 30 and 40
The multiples of 30 are 30,60,90,120 etc
The multiples of 40 are 40,80,120 etc
We can see that the lowest common multiple of both is 120
So therefore the spotlights will change colors at the same time after 120 seconds
Answer:
Option (a) is correct.
The system of equation becomes
Step-by-step explanation:
Given : Equation 
We have to construct a system of equations that can be used to find the roots of the equation
Consider the given equation
To construct a system of equation put both sides of the given equation equal to a same variable.
Let the variable be "y", Then the equation
becomes,
Thus, The system of equation becomes
Option (a) is correct.
In the form of algebra substitution is the method used in simultaneous equations.
E.g y=2x+5 and y=5x-1
Solve for x and y
Since we know two examples of what y is, we can substitute one y in replacement of the other to get.
2x+5=5x-1 then we solve for x to get:
x = 2 sub this back in to get y = 2(2) +5
y = 9
Answer:
50 – 5x = y and 46 – 4x = y, is your answer
