(a) (-3) × -9 = 27
WKT, 3 × 9 = 27
and -1 × -1 = 1
∴ (-3) × (-9) = 27
(b) 5 × -7 = -35
WKT,
5 × 7 = 35 and 1 × -1 = -1
∴ 5 × (-7) = -35
(c) 7 × (-8) = -56
WKT,
7 × 8 = 56
and 1 × -1 = -1
∴ 7 × (-8) = -56
(d) -11 × (-12)= 132
WKT,
11 × 12 = 132 and -1 × -1 = 1
∴ (-11) × (-12) = 132