Solution 1.1:2d

If we try and analyse the way the expression is constructed we see it is essentially a difference of two sub-expressions,

3(−7)−(4+6)(−5)

which can be calculated independently and then subtracted.

Examining the sub-expressions,the first is a product and the second a division

3(−7)−(4+6)(−5).

We thus can begin by calculating the numerator (4+6) in the second sub-expression

3(−7)−(4+6)(−5)=3(−7)−10(−5)

and then move over to the first sub-expression and do the multiplication

=3(−7)−10(−5)

=−21−10(−5)

and return to the division in the second sub-expression

=−21−10(−5)

=−21−(−2).

Finally we have an expression that can be calculated directly

=−21−(−2)

=−21+2

=−19.