Evaluate each expression.

19. [tex]g^5 - h^3[/tex] if [tex]g = 2[/tex] and [tex]h = 7[/tex]

20. [tex]c^2 + d^3[/tex] if [tex]c = 8[/tex] and [tex]d = -3[/tex]

21. [tex]a^2 \cdot b^6[/tex] if [tex]a = \frac{1}{2}[/tex] and [tex]b = 2[/tex]

22. [tex](r - s)^3 + r^2[/tex] if [tex]r = -3[/tex] and [tex]s = -4[/tex]



Answer :

Let's evaluate each expression one by one in detail.

### Expression 5: [tex]\( g^5 - h^3 \)[/tex] where [tex]\( g = 2 \)[/tex] and [tex]\( h = 7 \)[/tex]

1. Calculate [tex]\( g^5 \)[/tex]:
[tex]\[ g^5 = 2^5 = 2 \times 2 \times 2 \times 2 \times 2 = 32 \][/tex]

2. Calculate [tex]\( h^3 \)[/tex]:
[tex]\[ h^3 = 7^3 = 7 \times 7 \times 7 = 343 \][/tex]

3. Subtract [tex]\( h^3 \)[/tex] from [tex]\( g^5 \)[/tex]:
[tex]\[ g^5 - h^3 = 32 - 343 = -311 \][/tex]

So, [tex]\( g^5 - h^3 = -311 \)[/tex].

### Expression 10: [tex]\( c^2 + d^3 \)[/tex] where [tex]\( c = 8 \)[/tex] and [tex]\( d = -3 \)[/tex]

1. Calculate [tex]\( c^2 \)[/tex]:
[tex]\[ c^2 = 8^2 = 8 \times 8 = 64 \][/tex]

2. Calculate [tex]\( d^3 \)[/tex]:
[tex]\[ d^3 = (-3)^3 = -3 \times -3 \times -3 = -27 \][/tex]

3. Add [tex]\( c^2 \)[/tex] and [tex]\( d^3 \)[/tex]:
[tex]\[ c^2 + d^3 = 64 + (-27) = 64 - 27 = 37 \][/tex]

So, [tex]\( c^2 + d^3 = 37 \)[/tex].

### Expression 11: [tex]\( a^2 \cdot b^6 \)[/tex] where [tex]\( a = \frac{1}{2} \)[/tex] and [tex]\( b = 2 \)[/tex]

1. Calculate [tex]\( a^2 \)[/tex]:
[tex]\[ a^2 = \left(\frac{1}{2}\right)^2 = \frac{1}{2} \times \frac{1}{2} = \frac{1}{4} \][/tex]

2. Calculate [tex]\( b^6 \)[/tex]:
[tex]\[ b^6 = 2^6 = 2 \times 2 \times 2 \times 2 \times 2 \times 2 = 64 \][/tex]

3. Multiply [tex]\( a^2 \)[/tex] and [tex]\( b^6 \)[/tex]:
[tex]\[ a^2 \cdot b^6 = \frac{1}{4} \times 64 = 16 \][/tex]

So, [tex]\( a^2 \cdot b^6 = 16 \)[/tex].

### Expression 12: [tex]\( (r - s)^3 + r^2 \)[/tex] where [tex]\( r = -3 \)[/tex] and [tex]\( s = -4 \)[/tex]

1. Calculate the difference [tex]\( r - s \)[/tex]:
[tex]\[ r - s = -3 - (-4) = -3 + 4 = 1 \][/tex]

2. Calculate [tex]\( (r - s)^3 \)[/tex]:
[tex]\[ (r - s)^3 = 1^3 = 1 \][/tex]

3. Calculate [tex]\( r^2 \)[/tex]:
[tex]\[ r^2 = (-3)^2 = (-3) \times (-3) = 9 \][/tex]

4. Add [tex]\( (r - s)^3 \)[/tex] and [tex]\( r^2 \)[/tex]:
[tex]\[ (r - s)^3 + r^2 = 1 + 9 = 10 \][/tex]

So, [tex]\( (r - s)^3 + r^2 = 10 \)[/tex].

In summary, the evaluated results for each expression are:
1. [tex]\( g^5 - h^3 = -311 \)[/tex]
2. [tex]\( c^2 + d^3 = 37 \)[/tex]
3. [tex]\( a^2 \cdot b^6 = 16 \)[/tex]
4. [tex]\( (r - s)^3 + r^2 = 10 \)[/tex]