Question

Answer 1

BT10:

a) \(\left(-457\right)+\left(-123\right)+23+237\)

\(=\left(-457+237\right)+\left(-123+23\right)\)

\(=\left(-220\right)+\left(-100\right)\)

\(=-320\)

b) \(\left(-135\right)+48+140+\left(-5\right)\)

\(=\left[\left(-135-5\right)+140\right]+48\)

\(=\left(-140+140\right)+48\)

\(=0+48\)

\(=48\)

Answer 2

BT11: 

a) \(329+64+\left(-329\right)+36\)

\(=\left(329-329\right)+\left(64+36\right)\)

\(=0+100\)

\(=100\)

b) \(\left(-464\right)+\left(-371\right)+564+71\)

\(=\left(-464+564\right)+\left(-371+71\right)\)

\(=100+\left(-300\right)\)

\(=-200\)