Solve for the value of k. Please help 10 min left

Answer:
k=13
Step-by-step explanation:
A straight line is 180 degrees, so 4k-7+3k+6=180-90=90
7k-1=90, k=13
Answer:
12k^2+3k-42
Step-by-step explanation:
if we multiply both values (4k-7)(3k+6) like that can gave is 12k^2+3k-42