(6 times square root of 3 + square root of 5)(square root of 3 - 4 times the squae root of 5)

I'm assuming your problem is this:

(6√3 + √5)(√3 - 4√5)

Multiplying:

6√9 - 24√15 + √15 - 4√25

I'll let you take it from here to combine like terms and simplify.

I hope this helps and is what you were asking.

To simplify the expression (6√3 + √5)(√3 - 4√5), we can use the distributive property of multiplication.

First, let's multiply the terms in the first parentheses by the terms in the second parentheses:
(6√3)(√3) + (6√3)(-4√5) + (√5)(√3) + (√5)(-4√5)

Next, simplify each product:
6√3 * √3 = 6√3 * √3 = 6 * 3 = 18

6√3 * -4√5 = -24√15

√5 * √3 = √15

√5 * -4√5 = -4√25 = -4 * 5 = -20

Now, let's combine like terms:
18 - 24√15 + √15 - 20

Combine the integers:
18 - 20 = -2

Combine the square roots:
-24√15 + √15 = -23√15

Therefore, the simplified expression is:
-2 - 23√15