Question

Question 109 (i)

Observe the following patterns and fill in the blanks to make the statements true:
$-5\times 4=-20$
$-5\times 3=-15=-20–(-5)$
$-5\times 2$ =____ = -15 – (-5)
$-5\times 1=$____=____
$-5\times 0=0=$____
$-5\times (-1)=5=$____
$-5\times (-2)=$_____=_____

Answer 1

By observing the pattern, we find that I st column is constant, i.e. -5, II nd column is decreasing by 1. III rd column is increasing by 5, IV th column is also increasing by 5 and V th column is constant, i.e. -5. So, accordingly,
I II III IV V
$-5\times 4=-20-5\times 3=-15=-20–(-5)-5\times 2=-10=(-15)–(-5)-5\times 1=-5=(-10)-(-5)-5\times 0=0=(-5)-(-5)-5\times (-1)=5=0–(-5)-5\times (-2)=10=5-(-5)$