(1 and 3 / 4 minus 0.87 5 minus 7 / 12) times (minus 1 and 1 / 7)

(1 and 3 / 4 minus 0.87 5 minus 7 / 12) times (minus 1 and 1 / 7)

(1 and 3 / 4 minus 0.87 5 minus 7 / 12) times (minus 1 and 1 / 7)
=(1 and 3 / 4-7 / 8-7 / 12) × (- 1 and 1 / 7)
=(7/4-7/8-7/12)×(-8/7)
=[7/4+(-7/8)+(-7/12)]×(-8/7)
=7/4×(-8/7)+(-7/8)×(-8/7)+(-7/12)×(-8/7)
= -2+1+2/3
= -2+5/3
= -6/3+5/3
= -1/3

Find the increasing interval of the function y = log with the base of 1 / 3 [cos (x / 3 + π / 4)]

Increasing interval of function y = log with 1 / 3 as base [cos (x / 3 + π / 4)]
Because the function y = log is based on 1 / 3, it is itself a decreasing function
So the increasing interval of the function y = log with 1 / 3 as the base [cos (x / 3 + π / 4)]
It is the minus interval of COS (x / 3 + π / 4), because cos (x / 3 + π / 4) > 0
K π is greater than or equal to X / 3 + π / 4 and less than π / 2 + K π
So 3K π - 3 π / 4 is greater than or equal to X and less than 3 π / 4 + 3K π

Five three plus what equals three five minus what equals ten nine times what equals nine ten divided by what

Indeed, it's confusing
5/3-3/5=（25-9）/15=16/15
Five molecules of three plus 16 out of 15 equals three molecules of five
3/5-9/10=-3/10
Five molecules three minus three tenths equals ten molecules nine
10/9÷（3/5）=（10*5）/（3*9）=50/27
27 out of 50 times 3 out of 5 is 9 out of 10

For a polynomial with only the letter X, its quadratic and primary coefficients are all - 1, and the constant term is - 2 / 3. Try to write this quadratic trinomial and find it
When x = - 1 / 2, the value of this polynomial

He's - X & sup2; - X-2 / 3
x=-1/2
Original formula = - 1 / 4 + 1 / 2-2 / 3 = - 5 / 12

Banana 3 yuan / kg, apple 5 yuan / kg, pay 50 yuan, get back 14 yuan, calculate how many kilograms of banana and apple to buy each
What's the formula

Banana + Apple = 50-14 = 36 yuan, suppose banana buy x kg, apple buy y kg, 3x + 5Y = 36, carry in positive integer calculation, x = 1,2,3 y=1,2,3,…… Find out x = 2, y = 6: x = 7, y = 3 answer: Banana buy 2kg, apple buy 6kg, or banana buy 7kg, apple buy 3kg, but there are many answers to this question, I answer

Calculation [2 / (M + n)] - (1 / 2) [(M + n) / Mn]

The original formula = (4mn-m & # 178; - 2mn-n & # 178;) / 2Mn (M + n)
=-(m²-2mn+n²)/(2m²n+2mn²)

1/2*x(x+4y)+2y^2

Hehe, upstairs is wrong
1/2*x(x+4y)+2y^2
=1/2*x^2+2xy+2y^2
=1/2*(x^2+4xy+4y^2)
=1/2*(x+2y)^2

Decomposition factor: (x2 + 16y2) 2-64x2y2

（x2+16y2）2-64x2y2=（x2+16y2+8xy）（x2+16y2-8xy）=（x+4y）2（x-4y）2 … (5 points)

Simple operation of 6 / 17 × 16 + 6 / 17

6 out of 17 times (16 + 1) equals 6

Simplify the formula (4x-2y & # 178;) - [5x - (X-Y & # 178;)] - x

（4x-2y²）-[5x-（x-y²）]-x
=4x-2y²-5x+x-y²-x
=-2x-3y²
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