Question

(-3a^ + 2a -5)+(7 -3a + 3a^) при a= -4,5

Answer 1

(-3a^ + 2a -5)+(7 -3a + 3a^)=-3a^ + 2a -5+7 -3a + 3a^=-а+2

a= -4,5

-а+2=-(-4,5)+2=4,5+2=6,5

Answer 2

To calculate the value of the expression (-3a^2 + 2a - 5) + (7 - 3a + 3a^) when a = -4.5, we first need to substitute the value of a into the expression and then perform the arithmetic operations.

Let's start by substituting a = -4.5 into the expression:

(-3(-4.5)^2 + 2(-4.5) - 5) + (7 - 3(-4.5) + 3(-4.5)^2)

Now, we'll simplify the expression step by step:

1. Evaluate (-4.5)^2: (-4.5)^2 = 20.25
2. Evaluate -3(-4.5)^2: -3 * 20.25 = -60.75
3. Evaluate 2(-4.5): 2 * (-4.5) = -9
4. Evaluate 3(-4.5)^2: 3 * 20.25 = 60.75
5. Evaluate 3(-4.5): 3 * (-4.5) = -13.5

Now, the expression becomes:

(-60.75 - 9 - 5) + (7 - (-13.5) + 60.75)

Continuing to simplify:

(-60.75 - 9 - 5) + (7 + 13.5 + 60.75)

Now, add the values inside each set of parentheses:

(-74.75) + (81.25)

Finally, add the two values together:

-74.75 + 81.25 = 6.5

So, the value of the expression (-3a^2 + 2a - 5) + (7 - 3a + 3a^) when a = -4.5 is 6.5.