В. 7 1/9 - 4 1/3 = 7 1/9 - 4 3/9 = 6 10/9 - 4 3/9 = 2 7/9
Ответ 2 7/9.
г. 2 2/7 - 1 3/5 = 2 10/35 - 1 21/35 = 1 45/35 - 1 21/35 = 24/35
Ответ 24/35.
д. 6 1/4 - 3 2/5 = 6 5/20 - 3 8/20 = 5 25/20 - 3 8/20 = 2 17/20
Ответ 2 17/20.
<span>6.4 (y-12.8)=3.2</span>
6,4y -6,4*12.8 = 3.2
<span>2 y - 2*12,8 =1
2y = 25,6+1
2y =26,6
e =26.6/2
y = 13,3</span>
Х = 259/37
х = 7
Проверка - 7*37 = 259
А) (1/6+2/3)*3
(1 + 2*2)/6 * 3 = 5/6 * 3 = 5/2 = 2 1/2
б) (17/30-2/15) :13
(17 - 2 * 2)/30 * 1/13 = 13/30 * 1/13 = 1/30
в) (1/8+3/4) :5
(1 + 2*3)/8 * 1/5 = 7/8 * 1/5 = 7/40
г) (4/3+1/9)*4
(4*3 + 1)/9 * 4 = 13/9 * 4 = 52/9 = 5 7/9
д) (1/2+1/3)*2
(1*3 + 1*2)/6 * 2 = 5/6 * 2 = 5/3 = 1 2/3
е) (1/2-1/3)*3
(1*3 - 1*2)/6 * 3 = 1/6 * 3 = 1/2
А)100+24/х=25х+24/х
(100+24)х=(25х+24)х
124х=25х^2+24х
124х-24х-25х^2=0
100х-25х^2=0
х(100-25х)=0
1)х=0
2)100-25х=0
25х=100
х=4
б)(324-36)/х=324/х-6
288/х=324-6х/х
288х=(324-6х)х
288х=324х-6х^2
288х-324х+6х^2=0
-36х+6х^2=0