Question

(a + 2)2 - a(9a + 4) при a = -1,2​

Answer 1

Ответ:

Раскроем скобки 1)2a+4-9a2-4a сократим подобные:2)-2a+4-9a2подставим a 3) - 2x(-1,2)+4-9x(-1,2)2

4)-6,56

Answer 2

а²+4а+4-9а²-4а = -8а²+4 = 4-8а² = 4*(1-2а²)

если а = -1, то 4*(1-2*(-1)²) = 4*(1-2*1) = 4*(1-2) = 4*(-1) = -4

если а=2, то 4*(1-2*4) = 4*(1-8) = 4*(-7) = -28

если а= -1,2, то 4*(1-2*1,44) = 4*(1-2,88) = 4*(-1,88) = -7,52

Answer 3

To evaluate the expression (a + 2)² - a(9a + 4) when a = -1.2, we substitute the value of a into the expression:

(-1.2 + 2)² - (-1.2)(9(-1.2) + 4)

Simplifying the expression inside the parentheses:

(0.8)² - (-1.2)(-10.8 + 4)

Calculating the values within the parentheses:

0.64 - (-1.2)(-6.8)

To simplify further, we can multiply -1.2 by -6.8:

0.64 - (8.16)

Subtracting 8.16 from 0.64:

-7.52

Therefore, when a = -1.2, the expression (a + 2)² - a(9a + 4) evaluates to -7.52.