twice a number minus 4 is less than three times the number. (define a variable, write an inequality, and solve for the problem)



Answer :

x will represent unknown
2x-4<3x
treat the < sign as a = sign
2x-4=3x
subtract 2x form both sides
-4=x
put the < sign back
-4<x
-4 is less than than x or
x is greater than -4

A variable is a letter representing a number (ex. 2a+8h=26 ..... a=5 & h=2 )

"Solving'' an inequality means finding all of its solutions. A "solution'' of an inequality is a number which when substituted for the variable makes the inequality a true statement.

Here is an example: Consider the inequality

When we substitute 8 for x, the inequality becomes 8-2 > 5. Thus, x=8 is a solution of the inequality

2n-4 < 3n                                        
+4
2n+4-4<3n+4
2n<3n+4


-3n
2n-3n<4
-n<4
/-1
n>-4