1)
1 5/7÷1 1/7=12/7÷8/7=12/7×7/8=3/1×1/2=3/2=1 1/2
2)
3 1/5÷2 2/15=16/5÷32/15=16/5×15/32=1/1×3/2=3/2=1 1/2
3)
5 2/3÷1/3-1 7/12×6=17/3×3/1-19/12×6/1=17/1×1/1-19/2×1/1=17/1-19/2=34/2-19/2=15/2=7 1/2
задача
всего240 га.
1 день =х
2 день =7/9х
х+7/9х=240
умножим х на 9 и 240 на 9
9х+7х=2160
16х=2160
х=2160÷16
х=135 (1 день)
135÷9×7=15×7=105 (2 день)
135+105=240
задача
3/4 кг.=1 4/5р
2 1/2 кг.=х р.
1 4/5÷3/4=9/5×4/3=3/5×4/1=12/5=2 2/5
2 1/2×2 2/5=5/2×12/5=1/1×6/1=6/1=6 т.руб.
4) 1/6х+5/12х=8,4
2/12х+5/12х=84/10
7/12х=84/10
х=84/10÷7/12=84/10×12/7=12/5×6/1
х=72/5=14 2/5
1/6×72/5+5/12×72/5=84/10
12/5+6/1=84/10
12/5+30/5=42/5=8 2/5=8 4/10
8,4=8,4
Пошаговое объяснение:
8,4=8 4/10=84/10
Пошаговое объяснение:
1)
7. 1/2 : 4. 1/2 = х : 3/25
4. 1/2 * х = 7. 1/2 * 3/25
4. 1/2х = 15/2 * 3/25
9/2х = 3/2 * 3/5
9/2х = 9/10
х = 9/10 : 9/2
х = 9/10 * 2/9
х = 2/10
х = 1/5
2)
24/х + 2 = 1/5
24/х = 1/5 - 2
24/х = 1/5 - 1. 5/5
24/х = -1. 4/5
24/х = -9/5
х = 24 : (-9/5)
х = 24 * (-5/9)
х = 8 * (-5/3)
х = -40/3
х = -13. 1/3
3)
у - 5/6 = 4/3
у = 4/3 + 5/6
у = 8/6 + 5/6
у = 13/6
у = 2. 1/6
4)
2/5 = 6/(х+3)
2 * (х+3) = 5 * 6
2х + 6 = 30
2х = 30 - 6
2х = 24
х = 24 : 2
х = 12
5)
5/6 = 15/(2х-3)
5 * (2х - 3) = 6 * 15
10х - 15 = 90
10х = 90 + 15
10х = 105
х = 105 : 10
х = 10,5
6)
12 : (4х)/5 = 20 : 1/4
4х/5 * 20 = 12 * 1/4
80х/5 = 12/4
16х = 3
х = 3 : 16
х = 3/16
