Question

How do you solve `145= - 3( 2+ 8b ) + 7`?

Answer 1

To solve this you will need to use the concept of expansion.

Explanation:

According to the algebraic acronym BEDMAS (brackets, exponents, division, multiplication, addition, subtraction) which states the order of operations that must be performed in an algebraic equation, since there are brackets in the question these must be dealt with first.

In order to eliminate the brackets, we must expand them, by distributing the -3 that lies outside the bracket to both of the terms inside the brackets. To do this, we simply multiply 2 and 8b by -3.

`145 = -3 (2 + 8b) + 7`
`145 = (-3)(2) + (-3)(8b) + 7`
`145 = -6 - 24b + 7`

Now, since the 24b can't be combined with anything else, we must use simply algebra to isolate b so that we can get the value of it. We do this by moving all of our other numbers over to the left side of the equation, leaving '24b' on the right side.

`145 = -6 - 24b + 7`
`145 +6- 7=-24b`
`144 = -24b`
`144/-24 = b`
`-6 = b`