Question

C^2-2cd+d^2:c^2-d^2 при c= 8:15, d=7:15

Answer 1

с²-2сd+d²\c²-d².

сначала упрощаешь. в числителе и знаменателе- формулы сокращенного умножения. сложим их и получим:

(с-d)²\(c-d)(c+d)

сократим и получим:

c-d\c+d

при данных значениях:

8\15-7\5: 8\15+7\5

Answer 2

To simplify the expression (c^2 - 2cd + d^2) / (c^2 - d^2) and evaluate it when c = 8/15 and d = 7/15, we'll first substitute these values and then perform the calculations step by step.

Step 1: Substitute the values of c and d into the expression: (c^2 - 2cd + d^2) / (c^2 - d^2) = ( (8/15)^2 - 2*(8/15)*(7/15) + (7/15)^2 ) / ( (8/15)^2 - (7/15)^2 )

Step 2: Simplify the expression: (c^2 - 2cd + d^2) / (c^2 - d^2) = ( (64/225) - (112/225) + (49/225) ) / ( (64/225) - (49/225) )

Step 3: Continue simplification: (c^2 - 2cd + d^2) / (c^2 - d^2) = ( (64/225 - 112/225 + 49/225) ) / ( (64/225 - 49/225) ) = ( (-48/225) ) / ( (15/225) ) = -48/15

Step 4: Reduce the fraction to its simplest form: -48/15 = -16/5

So, the simplified expression when c = 8/15 and d = 7/15 is -16/5.