Answer:
The first car was traveling 70 mph, while the second was driving 50 mph.
Step-by-step explanation:
Set the cars as a proportion:

X represents the speed of the second car. By cross multiplying, you get the following equation:

You solve by distributing 150 to get 210x = 150x + 3000.
Solving for x gets you 50.
That means the first car was going at 50 mph. Adding 20, you get 70 as the speed for the second car.
Answer:
Step-by-step explanation:
X = number of Yan's marbles. x-3 = number of Geraldo's marbles
annswer: x + (x - 3) = 21
hopes this helps :)
Hey there!
The main concept of pre-algebra is solving equations for variables in them.
For example, let's say you have the algebraic equation below.
x+1=3
With algebra, you need to figure what x is equal to. To do so, you will use inverse operations on both sides of the equation to isolate x one side, showing what it is equal to.
We would subtract 1 to both sides to isolate x on one side.
x+1-1=3-1
As you can see, +1-1=0, therefore, this would give us x+0, or just x. Now it is isolated and will show us what it is equal to.
x=3-1
x=2
Therefore, in our equation x+1=3, x would be equal to 2.
I hope this explanation helps! Have a great time here at Brainly!
(11k^4 - 4m) + (-2k^4 - 15m)
Add -2k^4 to 11k^4. This would be the same as subtracting 2k^4 from 11k^4
9k^4 - 4m - 15m
Add -15m to -4m. This would be the same as subtracting 15m from -4m
Final Answer: 9k^4 - 19m
Word Form: Nine times the variable k to the forth power minus nineteen times the variable m.
31.5 pencils used in 1 hour