((-b) - a) * ((-b) + a) = (-b)² - a² = b² - a²
4/5t+4/15+2/3t=14/5t+2/3t=1-4/15
12/15 t + 10/15 t =11/15
22/15 t= 11/15
t= 11/15 : 22/15
t= 11/15 * 15/22
t=1/2
1)(1 3/5+1,8)*1/2=1,7
8/5+18/10=16/10+18/10=34/10=17/5
17/5*1/2=17/10=1,7
2)(6-4 8/15):2,2=2/3
6-4 8/15=6/1-68/15=90/15-68/15=22/15
22/15:2,2=22/15*10/22=2/3
3)(1,25+1/6)*2,4=3,4
1,25+1/6=5/4+1/6=15/12+2/12=17/12
17/12*2,4=17/12*24/10=34/10=3,4
<h3>Решение:</h3><h2>1</h2>
2.3x = 6.9
x = 6.9 : 2.3
х = 3
<h2>2</h2>
5.6х = 11.2
х = 11.2 : 5.6
х = 2
<h2>3</h2>
-х = 6
х = -6
<h2>4</h2>
1.2х = 0
х = 0 : 1.2
х = 0
ax + b = 0,
Где а и b - некоторые числа, а x - неизвестная переменная.