Answer:
Equation: 3X- 11 = 85
Solution: X = 32
Explanation:
First pick a variable to represent the number. Let's call this variable X
Though you could choose any single letter as a variable and also as uppercase x and X are usually chosen when there is only one unknown but strictly speaking there is no restriction as long as you specify what the variable is and what it represents.
X = a number
"three times a number" is represented by multiplying X by 3 giving 3X
"three times a number minus 11" is represented by 3X - 11
"is the same as 85" is represented by =85
So the equation is
3X- 11 = 85
To solve the above equation we have to "isolate" the X term ie make sure it is the only term on the left side of the equation
To achieve this:
Add 11 to both sides of the equation
3X - 11 + 11 = 85 + 11
-11 + 11 = 0 and 85 + 11 = 96
So we get 3X + 0 = 96
3X = 96
Divide both sides by 3
3X/3 = 96/3
3X/3 = X and 96/3 = 32
So we get X = 32 which is the solution to the above equation
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It is always a good idea to verify our calculations by plugging in this value of X into the left side of the equation and seeing it is equal to the value on the right side
3X - 11 ==> 3(32) - 11 = 96 - 11 =85
so the equation is satisfied with X = 32
Hope that helps :)