Solve the following system by using substitution: 3y=6x+9 and y=4x+9

X=-3, and Y=-3. First, get Y by itself so 3y=6x+9 will be Y=2x+3, then set the equations equal. Then you can solve for x. Then Substitute x=-3 in for x and you will get Y=-3.

Historians are researchers of the past or people who understand the history of people. with this field, they must possess qualities such as being unbiased, patient, efficient reader, has a knack for logic and critical thinking and reasoning, disciplined, open-minded, resourceful, with good analytical ability, good reasoning skills and problem solving!

D. a mountain abd are made by volcanos and tectonic plates