To find the value of a variable you must know the basics of pre-Algebra.
Example:
2x+9=39
To find he answer of this you must subtract 9 from both sides
Then you are left with…
2x=30
Since 2x=30 means 2 times x equals 30
You can divide 2 from both sides to find the answer
Which is…
x=15
Answer:
202
Step-by-step explanation:
200 + 0 make sure to add 2
201+ 1
202+ 2
60 miles per hour. In two miles the sum of the distance the two trains traveled was 200 miles, you divide that by 2, the sum of the speed of the two trains is 100 miles per hour, now put the speed of the slow train as x and the fast as x +20, the sum of x and x +20 is 100, so 2x + 20 =100, you subtract 20 from both sides, 2x = 80, divide by 2, x = 40, the problem asks for the speed of the fast train, so, x + 20 is 60.
