999 * 222 + 666 * 667 (with simple algorithm) How to calculate ah, who knows ah, I am a primary school math enthusiast, but I encountered a problem, please junior high school,

999 * 222 + 666 * 667 (with simple algorithm) How to calculate ah, who knows ah, I am a primary school math enthusiast, but I encountered a problem, please junior high school,

222×999＋666×667
=222*3*333+666*667
=666*333+666*667
=666*(333+667)
=666*1000
=666000

Simple calculation of 222 × 999

222×999
=222×（1000-1）
=222×1000-222×1
=222000-222
=221778

Three squares side by side, the sum of angle 1 and angle 2 equals 45 degrees

1.cos∠AOB＝ cos（∠AOD-∠BOD）＝1/√2·2/√5+1/√2·/√5＝3/√10
2. Connect C2. ⊿ OAB ⊿ O2C (three sides are proportional), ∠ cod = ∠ AOB
∠BOD+∠COD＝∠BOD+∠AOB＝∠AOD＝45°
You first set my best answer, I Baidu HII teach you

90 degrees - 32 degrees 23 minutes 17 seconds 98 degrees 45 minutes 36 seconds + 71 degrees 22 minutes 34 seconds 103.3 degrees + 176 degrees 42 minutes
be equal to

Minutes and seconds are in the base of 60 (, in fact, they are degrees minus degrees, minutes minus minutes, seconds minus seconds. When it's not enough to reduce, the front one is less than one unit, and the subtraction plus 60, your questions here are all enough to reduce, the simplest). So the first question is equal to 57 degrees 36 minutes 43 seconds (regarding 90 degrees as 89 degrees 59 minutes 60 seconds, and subtracting the following degrees, minutes and seconds correspondingly). The second question is equal to

What is 78 / 1 + 52 / 1

The final answer is 130

78°32′-51°47′= 45°37′29′′-11°23′26′′*3= 176°52′/3=

78°32′-51°47′= 26°45'
45°37′29′′-11°23′26′′*3
=45°37'29''-34°10'18''
176°52′/3=58°57'20''

3.78 + (6.22 + 4.72) 18.73 + 3.85-2.73 45.6 - (83.7-78.8)

3.78+（6.22+4.72）
=3.78+6.22+4.72
=10+4.72
=14.72
18.73+3.85-2.73
=18.73-2.73+3.85
=16+3.85
=19.85
45.6-（83.7-78.8）
=45.6-4.9
=45.6-5+0.1
=40.6+0.1
=40.7

9.7-22.78 △ 3.4 3.7 simple calculation

9.7-22.78÷3.4 +3.7
=9.7 -6.7+3.7
=3+3.7
=6.7

Simple calculation of 4.12-1.78-1.22

4.12－1.78－1.22
＝4.12－（1.78＋1.22）
＝4.12－3
＝1.12

The square of a + 1 divided by A-1 equals

This problem you should have the following. According to the conditions to the simplest
There are two results
1）a+1+2/(a-1)
2）a-1+2a/(a-1)
It should be to prove inequality