Essentially when people ask you find the solution to system of equation, there asking at what x value do these to graphs intersect. The easiest way to do this is to get a graphing calculator, or desmos and type in the equation and find where they intersect. Heck, even the question says to solve it with a graph, but I'll demonstrate it algebraically.
One way you can do this is set the equation equal to each other. This is because you want to know at what x-value has the same y-value. So we get:
x^2 + 6x + 8 = x + 4
We can then combine like terms, or move everything to one side. So we get:
x^2 + 5x + 4 = 0.
Then we can use the quadratic formula to solve for x.
x=(-5 +/- sqrt(5^2 - 4(1)(4)))/(2(1)
This simplifies into:
(-5 +/- 3)/2
Finally we add and subtract:
(-5 + 3)/2 = x = -1
(-5 - 3)/2 = x = -4
And our solution is x = -1, x = -4
Answer:
In traffic, she drove for 3 hours
and After the traffic cleared she drove for 2 hours.
Explanation:
Given that the road trip was 136 miles;
The first part of the trip there was lots of traffic, she only averaged 16 mph;
The second part of the trip there was no traffic so she could drive 44 mph;
She traveled for a total of 5 hours;
let x represent the time in traffic when she traveled at 16 mph
the time the traffic is clear would be;
Recall that distance equals speed multiply by time;
substituting the values;
solving for x;
So;
Therefore, In traffic, she drove for 3 hours
and After the traffic cleared she drove for 2 hours.
This question is worded slightly strangely but I believe I understand it.
To eliminate x, multiply the second equation by 8, so that it becomes 4x + .8y= 96
Then you can subtract 4x on the top by 4x on the bottom to eliminate it.
So, if k/9=3/9, then k=3, because it is a variable substituting 3. :D Hope I could help!
