sin150<span>°</span>+sin75<span>°</span>=sin(180<span>°</span>-150<span>°</span>)+sin(30<span>°</span>+45<span>°</span>)= -sin30<span>°</span>+sin30<span>°*cos45<span>°+sin45<span>°*cos30<span>°= -1/2+ 1/2* <span>√2/2+ <span>√2/2*<span>√3/2= -1/2+<span>√2/4+<span>√6/4=(<span>√2+<span>√6-2)/4=<span>√2(1+<span>√3-<span>√2)/4</span></span></span></span></span></span></span></span></span></span></span></span></span></span>
<span><span><span><span><span><span><span><span><span><span><span><span><span><span>Ну как-то так</span></span></span></span></span></span></span></span></span></span></span></span></span></span>
В минуте 60 секунд. 60:10=6 6х2=12
12 слов.
10х=7490 90900:х= 10
х= 7490:10 х= 90900:10
х=749 х= 9090
х×10=40070
х= 40070:10
х = 4007
80÷4·3=60
осталось прочитать 20 страниц ,что составляет 1/4 книги
60/20=3 в 3 раза
1...
2х+17=0
2×=-17
×=-17/2
×=-8.5
22+3×=0
3×=-22
×=-22/3
×=-7.3 ..(3) -8.5не ровно-7.3... (3)
2....
18+3х=0
3×=-18
×=-18/3
×=-6
×+14
×=-14 -6 Не ровно-14
3....
25-4×=0
-4х=-25/(-1)
х= 25/4
х=8,125
12-5×=0
-5×=-12/(-1)
х=12/5
х=2.4 8,125не равно 2.4