Question

Упростите выражение:
1)a-154a-20 - a-5/4a+20 + 30a²-25;
2)8a³+100aa³+125 - 4a²a²-5a+25.
Помогите пожалуйста !!! Срочно нужно !!!!

Answer 1

1)(a - 15)(4a - 20) - (a - 5)/(4a + 20) + 30(a² - 25) = (a - 15)4(a - 5) - (a - 5)/4(a + 5)+
+ 30(a - 5)(a + 5) = (a - 15)(a + 5)/4(a - 5)(a + 5) - (a - 5)(a - 5)/4(a + 5)(a - 5) + (30 · · 4)/4(a - 5)(a + 5) = ((a - 15)(a + 5) - (a - 5)(a - 5) + 120)/4(a - 5)(a + 5) = (a²-15a+5a- - 75 - (a² - 10a + 25) + 120)/4(a - 5)(a + 5) = (a² - a² - 15a + 5a + 10a - 75 - 25 + 120) /4(a - 5)(a + 5) = (-10a + 10a - 100 + 120)/4(a - 5)(a + 5) = 20/4(a - 5)(a + 5) = 5/(a² - - 25)
2)(8a³ + 100a)(a³ + 125) - (4a²)(a² - 5a + 25) = (8a³ + 100a)(a + 5)(a² - 5a + 25) -(4a²)/(a² - 5a + 25) = (8a³ + 100a)(a + 5)(a² - 5a + 25) - (4a²)(a + 5)/(a + 5)(a² - 5a + + 25) = ((8a³ + 100a) - (4a³ + 20a²))/(a + 5)(a² - 5a + 25) = (8a³ + 100a - 4a³ - 20a²)/
/(a + 5)(a² - 5a + 25) = (4a³ + 100a - 20a²)/(a + 5)(a² - 5a + 25) = 4a(a² - 5a + 25)/
/(a + 5)(a² - 5a + 25) = 4a/(a + 5)