Mows 3/8 of lawn & uses3/4gal of gas. What fraction of lawn can be mowed per gallon

Sam claims that cos x =sin y if x and y are congruent angels. is sam correct ?

The vertex of this parabola is at (-2,-3). when the x-value is -1, the y-value is -5. what is the coefficient of the squared expression in the parabola's equation?

The fence around a quadrilateral-shaped pasture is 3a^2+15a+9 long. three sides of the fence have the following lengths: 5a, 10a-2, a^2-7. what is the length of the fourth side of the fence?