Evaluate the following expressions:

a. [tex]\[ -7x^3 + 3x^2 + 11x - 9 \][/tex] for [tex]\[ x = -2 \][/tex]

b. [tex]\[ 4y^2 - 3y + 8 \][/tex] for [tex]\[ y = -3 \][/tex]

c. [tex]\[ 14x^2 y + 3xy^2 + 2xy - 5 \][/tex] for [tex]\[ x = 1 \][/tex] and [tex]\[ y = 2 \][/tex]



Answer :

Sure, let's evaluate each expression step-by-step:

### Part a:
Evaluate the expression [tex]\(-7x^3 + 3x^2 + 11x - 9\)[/tex] for [tex]\(x = -2\)[/tex].

1. Substitute [tex]\(x = -2\)[/tex] into the expression:
[tex]\[-7(-2)^3 + 3(-2)^2 + 11(-2) - 9\][/tex]

2. Next, calculate each term:
[tex]\((-2)^3 = -8\)[/tex]
[tex]\[-7 \cdot (-8) = 56\][/tex]

[tex]\((-2)^2 = 4\)[/tex]
[tex]\[3 \cdot 4 = 12\][/tex]

[tex]\[11 \cdot (-2) = -22\][/tex]

3. Combine these results:
[tex]\[56 + 12 - 22 - 9\][/tex]

4. Simplify:
[tex]\[56 + 12 = 68\][/tex]
[tex]\[68 - 22 = 46\][/tex]
[tex]\[46 - 9 = 37\][/tex]

So, the result for part a is [tex]\(\boxed{37}\)[/tex].

### Part t:
Evaluate the expression [tex]\(4y^2 - 3y + 8\)[/tex] for [tex]\(y = -3\)[/tex].

1. Substitute [tex]\(y = -3\)[/tex] into the expression:
[tex]\[4(-3)^2 - 3(-3) + 8\][/tex]

2. Next, calculate each term:
[tex]\((-3)^2 = 9\)[/tex]
[tex]\[4 \cdot 9 = 36\][/tex]

[tex]\[-3 \cdot (-3) = 9\][/tex]

3. Combine these results:
[tex]\[36 + 9 + 8\][/tex]

4. Simplify:
[tex]\[36 + 9 = 45\][/tex]
[tex]\[45 + 8 = 53\][/tex]

So, the result for part t is [tex]\(\boxed{53}\)[/tex].

### Part c:
Evaluate the expression [tex]\(14x^2y + 3xy^2 + 2xy - 5\)[/tex] for [tex]\(x = 1\)[/tex] and [tex]\(y = 2\)[/tex].

1. Substitute [tex]\(x = 1\)[/tex] and [tex]\(y = 2\)[/tex] into the expression:
[tex]\[14(1)^2(2) + 3(1)(2)^2 + 2(1)(2) - 5\][/tex]

2. Next, calculate each term:
[tex]\((1)^2 = 1\)[/tex]
[tex]\[14 \cdot 1 \cdot 2 = 28\][/tex]

[tex]\[(2)^2 = 4\][/tex]
[tex]\[3 \cdot 1 \cdot 4 = 12\][/tex]

[tex]\[2 \cdot 1 \cdot 2 = 4\][/tex]

3. Combine these results:
[tex]\[28 + 12 + 4 - 5\][/tex]

4. Simplify:
[tex]\[28 + 12 = 40\][/tex]
[tex]\[40 + 4 = 44\][/tex]
[tex]\[44 - 5 = 39\][/tex]

So, the result for part c is [tex]\(\boxed{39}\)[/tex].

In summary, the results are:
- Part a: [tex]\(\boxed{37}\)[/tex]
- Part t: [tex]\(\boxed{53}\)[/tex]
- Part c: [tex]\(\boxed{39}\)[/tex]