Question

(2k-c)(2k+c)+(c-0.5k)(c+0,5k)при k=0.4, c=1.7​

Answer 1

(2k)^2-c^2+c^2-(0.5k)^2=4k^2-c^2+c^2-0.25k^2=4.25k^2+2c^2

Answer 2

To evaluate the expression (2k-c)(2k+c) + (c-0.5k)(c+0.5k) when k = 0.4 and c = 1.7, simply substitute these values into the expression and perform the calculations:

(2 * 0.4 - 1.7)(2 * 0.4 + 1.7) + (1.7 - 0.5 * 0.4)(1.7 + 0.5 * 0.4)

Now, let's calculate each part:

(2 * 0.4 - 1.7) = (0.8 - 1.7) = -0.9 (2 * 0.4 + 1.7) = (0.8 + 1.7) = 2.5

(1.7 - 0.5 * 0.4) = (1.7 - 0.2) = 1.5 (1.7 + 0.5 * 0.4) = (1.7 + 0.2) = 1.9

Now, put these values back into the main expression:

(-0.9)(2.5) + (1.5)(1.9)

Now, perform the multiplications:

-2.25 + 2.85

Finally, add the two results together:

-2.25 + 2.85 = 0.6

So, when k = 0.4 and c = 1.7, the expression (2k-c)(2k+c) + (c-0.5k)(c+0.5k) evaluates to 0.6.