Answer:
Train A - 50 miles per hour
train B - 30 miles per hour
Step-by-step explanation:
Let x mph be the speed of the train B, then the speed of the train A is (x+20) mph.
In 3 hours,
- train A travels 3(x+20) miles
- train B travels 3x miles
In total, they covered the distance of 240 miles, so
![3(x+20)+3x=240\ \ \ \text{[Divide by 3]}\\ \\x+20+x=80\\ \\2x=80-20\\ \\2x=60\\ \\x=30\ mph\\ \\x+20=30+20=50\ mph](https://tex.z-dn.net/?f=3%28x%2B20%29%2B3x%3D240%5C%20%5C%20%5C%20%5Ctext%7B%5BDivide%20by%203%5D%7D%5C%5C%20%5C%5Cx%2B20%2Bx%3D80%5C%5C%20%5C%5C2x%3D80-20%5C%5C%20%5C%5C2x%3D60%5C%5C%20%5C%5Cx%3D30%5C%20mph%5C%5C%20%5C%5Cx%2B20%3D30%2B20%3D50%5C%20mph)
Answer:
Step-by-step explanation:
This question is asking you to insert two equations, f(x) and g(x), into the equation g(x) - f(x). This will lead to the equation below.
Now we can solve for the equation.
The equation of an ellipse is x²/a² + y²/b² =1
a being the distance between the center & x intercept =7
b being the distance between the center & y intercept =5
Hence the equation of this ellipse is:
x²/49 + y²/25 =1
Answer: it think its A
Step-by-step explanation:
The area is given by
A = (5 + 2x) * (10 + 2x) - 50
Rewriting we have:
A = 50 + 10x + 20x + 4x ^ 2 -50
Rewriting we have:
A = 4x ^ 2 + 30x
Substituting the value of the area we have:
54 = 4x ^ 2 + 30x
Rewriting:
4x ^ 2 + 30x - 54 = 0
We look for the roots:
x1 = -9
x2 = 3/2
We take the positive root:
x2 = 3/2
Answer:
the value of x is:
x = 3/2
