When calculating the decimal addition and subtraction method, Congcong mistook the subtraction 25.7 as 52.7, and the result was equal to 13.6. What should be the correct result?
Right
52.7-25.7+13.6
=27+13.6
=40.6
If you don't understand this question, you can ask,
(x ^ 2 + y ^ 2) / (x ^ 2-y ^ 2) minus (x + y) / (2x-2y), simplify
My calculation is: x ^ 2-2xy + y ^ 2, which is different from others,
You left out the denominator (x ^ 2 + y ^ 2) / (x ^ 2-y ^ 2) - (x + y) / (2x-2y) = (x ^ 2 + y ^ 2) / (X-Y) (x + y) - (x + y) / 2 (X-Y) = 2 (x ^ 2 + y ^ 2) / 2 (X-Y) (x + y) - (x + y) ^ 2 / 2 (X-Y) (x + y) = [2 (x ^ 2 + y ^ 2) - (x + y) ^ 2] / 2 (X-Y) (x + y) = [2x ^ 2 + 2Y ^ 2 - (x ^ 2 + y ^ 2 + 2XY)] / 2 (x -
First simplify, then calculate. (x ^ 2-9 / x + 2) divided by (x ^ 2-6x + 9 / 2x + 4) minus (2x / x)
First simplify, then numerical
(x ^ 2-9 / x + 2) divided by (x ^ 2-6x + 9 / 2x + 4) minus (2x / x-3), where x equals 1
(x^2-9/x+2)÷(x^2-6x+9/2x+4)-(2x/x-3)
=[(x-3)(x+3)/(x+2)]×[2(x+2)/(x-3)²]-2x/(x-3)
=2(x+3)/(x-3)-2x/(x-3)
=6/(x-3)
=6/(1-3)
=-3