1.) Given that WD and DY must be equal, you can create an equation to solve to for x, then use x to solve for WY!
To solve for x, set WD and DY equal to each other:
x + 1 = -7 + 2x
Subtract 2x from both sides:
-x + 1 = -7
Subtract 1 from both sides:
-x = -8
x = 8
Add WD and DY given x to solve for WY:
(x + 1) + (-7 + 2x) = WY
(8 + 1) + (-7 + 2(8)) = WY
(9) + (-7 + 16) = WY
9 + (9) = WY
WY = 18
2.) To find x, first recognize that the angle you are solving for must be equal to the angle opposite of it (86 degrees). Given this, you can set up an equation to solve for x.
11x - 2 = 86
Add 2 to both sides:
11x = 88
Divide both sides by 11 to solve for x:
x = 8
3.) To find x, first recognize that the angle you are solving for is equal to 90 degrees given that it exists within a rectangle. Given this, you can set up an equation to solve for x.
(2x+7) + (6x+3) = 90
Combine like terms:
8x + 10 = 90
Subtract 10 from both sides:
8x = 80
Divide both sides by 8 to solve for x:
x = 10