Evaluate $7.4\times\left(-4.1\right)$7.4×(−4.1).

Evaluate $8\times\left(-2.4\right)$8×(−2.4).

Evaluate $-7.6\times7.8$−7.6×7.8.

Evaluate $1.99\times\left(-8\right)$1.99×(−8).