Simplify the expression. 7t^4 x 7t^4

49t^8

Simplify the expression. -x(5x-4)

-5x^2+4x

Simplify the expression. 5k^2(-6k^2-2k+6)

-30k^4-10k^3+30k^2

Simplify the expression. (2k+3)(k-1)

2k^2+k-3

Simplify the expression. (-3y+2)(y+3)

-3y^2-7y+6

To simplify the expression 7t^4 x 7t^4, we need to multiply the coefficients and combine the powers of t.

The coefficient of both terms is 7. So, we multiply 7 by 7 to get 49.

Now, let's look at the powers of t. When you multiply variables with the same base, you add their exponents.

In this case, t^4 x t^4 = t^(4+4) = t^8.

So, the simplified expression is 49t^8.