Video Transcript
Evaluate 𝑎 minus 𝑏 if 𝑎 equals
one-seventh and 𝑏 equals negative five-sevenths.
In this question, we are given an
algebraic expression involving 𝑎 and 𝑏 and asked to evaluate this expression using
the given values of 𝑎 and 𝑏. We evaluate the expression by
substituting the values of 𝑎 and 𝑏 into the expression to obtain one-seventh minus
negative five-sevenths.
We can then recall that subtracting
a negative number is the same as instead adding the positive number. So, we can rewrite this expression
as one-seventh plus five-sevenths. We can then note that we are adding
two fractions with the same denominator. So, we can combine these into a
single fraction by adding their numerators. We get one plus five all over
seven, which evaluates to give six-sevenths.
