To solve an equation involving two or more operations, start by carrying out
an inverse operation on the number that is furthest away from x.
Example 8
Solve 7x + 4 = 25.
Solution:
The number 4 is furthest away from x. The inverse of + 4 is
– 4. So, subtract 4 from both sides.

Problem Solving 2
Example 9
If three times a number, when diminished by 4, equals 17, what is the
number?
Solution:
Let x be the number.
Three times x is 3x, and diminishing this by 4 gives 3x
– 4, which we are told equals 17.

So, the number is 7.
|