Key to this problem! Distribution!
-7x(11x+12)
Imagine -7x going to both 11x and 12. Meaning it would multiply with both those numbers. If helpful, write arrows that it goes to both numbers inside the parenthesis to help you out.
-7x(11x)+12(-7x)
-7 x 11 is -77, and x times x is x^2, so the first part would equal to -77x^2
12 x -7 is -84, and add a x to get -84x.
The final answer is -77x^2-84x