Angle a = 56 degrees, angle abd = 20 degrees, angle ACO = 32 degrees

Angle a = 56 degrees, angle abd = 20 degrees, angle ACO = 32 degrees

Triangle inner angle and 180 ° angle, ADB = 92 °

30 + 40 + 38 + 2:51 + 40 + 1:32 = when?

6:51
It seems that

How many seconds is 51 days?

4406400

What is (40-x) (x-20-1) - 12.5-10?

=（40-x）（x-21）-22.5
=40x-840-x²+21x-22.5
=-x²+61x-862.5
Δ = 271 is not a square number
So it can't be decomposed
Hope to adopt

Equation x-40% X-5 (40% X-5) * 80% = 12
Write the formula

x-0.4x-5(0.4x-5)*0.8=12
x-0.4x-4(0.4x-5)=12
0.6x-1.6x+20=12
-x=-32
x=32

80%x-40%x=3

80%x-40%x=3
（80％－40％）x＝3
40％x＝3
x＝3÷40％
x＝7.5

X = (60% x-40) + (one third x + 80)
The number of boys in Xinhua primary school is 40 less than 60% of the total number of the school, and the number of girls is 80 more than one third of the total number of the school. How many students are there in this school?
A batch of goods will be delivered in three times. For the first time, a quarter of this batch of goods were still 3 tons more, for the second time, two fifths of this batch of goods were less than 4 tons, and for the third time, 29 tons. How many tons are there in total?

1: Let the total number of students in the school be X
The number of boys is 60% x-40,
The number of female students is 1 / 3x + 80,
Total number of students x = number of girls + number of boys
So: x = (60% x-40) + (one third x + 80)
2: Suppose there are x tons in total
Then: 1 / 4x + 3 for the first time
2 / 5x-4 for the second time
29 for the third time
So this batch of goods = the first time + the second time + the third time
x=1/4x+3+2/5x-4+29
x=80

(1 + 40%) x · 80% or (1 + 40%) x × 80%? Do you use "·" or "×"?

X

X(1+40％)×80％—X＝10％X
How to find the result of this formula? Good answer plus points
It's better to write the method clearly

X(1+40％)*80％—X＝10％X
X(1+40％)*80％—X—10％X ＝0
X[(1+40％)*80％—1—10％]=0
X=0
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x+20*40%=80
emergency

x+20*40%=80
x=80-20*40%
x=80-20*0.4
x=80-8
x=72