Answer :

Sure, let's break down the problem step by step.

Given values:
[tex]\( a = 4 \)[/tex]
[tex]\( b = 5 \)[/tex]

We need to find the value of the expression:
[tex]\[ 6a^2 - 2ab \][/tex]

### Step 1: Calculate [tex]\(a^2\)[/tex]

First, we find the square of [tex]\(a\)[/tex]:

[tex]\[ a^2 = 4^2 = 16 \][/tex]

### Step 2: Multiply [tex]\(a^2\)[/tex] by 6

Next, we multiply the result by 6:

[tex]\[ 6a^2 = 6 \times 16 = 96 \][/tex]

### Step 3: Calculate the product of [tex]\(a\)[/tex] and [tex]\(b\)[/tex]

Now, we find the product of [tex]\(a\)[/tex] and [tex]\(b\)[/tex]:

[tex]\[ ab = 4 \times 5 = 20 \][/tex]

### Step 4: Multiply [tex]\(ab\)[/tex] by 2

Then, we multiply the result by 2:

[tex]\[ 2ab = 2 \times 20 = 40 \][/tex]

### Step 5: Subtract [tex]\(2ab\)[/tex] from [tex]\(6a^2\)[/tex]

Finally, we subtract the value obtained in Step 4 from the value obtained in Step 2:

[tex]\[ 6a^2 - 2ab = 96 - 40 = 56 \][/tex]

So, the value of the expression [tex]\( 6a^2 - 2ab \)[/tex] is:

[tex]\[ \boxed{56} \][/tex]