3x - 12y = -30 and x - 6y = -12

Prove that the sum of two consecutive exponents of the number 5 is divisible by 30.if two consecutive exponents are 5n and 5n + 1, then their sum can be written as 30.

Solve the system of equations using the substitution method. {y=−3x+7x=−2y−16 enter your answers in the boxes.

From the top of a tree a bird looks down on a field mouse at an angle of depression of 50°. if the field mouse is 40 meters from the base of the tree, find the vertical distance from the ground to the bird's eyes.