First, let's substitute a=90 into the first expression:
(0, 4(90)+3) - (0, 5(90)-6)(0, 360+3) - (0, 450-6)(0, 363) - (0, 444)(0, -81)
For the second expression, let's substitute a=0 and b=-0.8:
(3(0)+7(-0.8)) - (4(0)+3(-0.8))(0-5.6) - (0-2.4)-5.6 + 2.4-3.2
Therefore, the results for the given expressions are:
1) (0, -81)2) -3.2
First, let's substitute a=90 into the first expression:
(0, 4(90)+3) - (0, 5(90)-6)
(0, 360+3) - (0, 450-6)
(0, 363) - (0, 444)
(0, -81)
For the second expression, let's substitute a=0 and b=-0.8:
(3(0)+7(-0.8)) - (4(0)+3(-0.8))
(0-5.6) - (0-2.4)
-5.6 + 2.4
-3.2
Therefore, the results for the given expressions are:
1) (0, -81)
2) -3.2