Question

20. Integers a, b, c, d are such that -5 = a = 4, -2 = b= 6, -3 = c = 8 and -4 = d = 6.If X = ab+bc+cd+da, then find the least value of X?

a.-96
b.-72
c.48
d.-144

Answer 1

Answer:

a. -96

Step-by-step explanation:

So, we have equation X = ab+bc+cd+da. And we need to find the least value of X.

a=-5; 4

b=-2; 6

c=-3; 8

d=-4; 6

Let's try to find a combination for each pair of equation(like ab) so that the answer has the smallest number. So, a=-5; 4. b=-2; 6. As one can observe, the smallest result comes out with this combination: ((-5)*6)=-30. All we need to do is to repeat this actions with the rest of pairs.

Eventually. Here is the solution:

ab+bc+cd+da=x=((-5)*6)+(6*(-3))+((-3)*6)+(6*(-5)) = (-30) + (-18) + (-18) (-30) = -96