If (4x + 3y + 9) (3x + 7y – 8) is equal to ax² + by² + cxy + dx + ey – f, Find the value of a+b+c/d-e÷f
a) -8.43
b) -9.84
c) -3.64
d) -2.67
Sol:
(4x + 3y + 9) (3x + 7y – 8) =
21y² + 12x² + 37xy – 5x + 39y – 72 = equation.
a = 12
b = 21
c = 37
d = -5
e = 39 f = 72
