Let those 2 numbers be x and y, with x>y (needed for the subtraction to put the bigger number first to get a positive answer). "The difference of the two numbers is 36" can be represented by the equation x - y = 36 "Their sum is 286" can be represented by the equation x + y=286.
We can now create a system: x - y = 36 (1) x + y = 286 (2)
In the equation (1), let's find the value of x: x - y = 36 Add y in both sides so we can get x on a side and its value on the other: x - y + y = 36 + y x = 36 + y
In the equation (2), let's replace x by its found value to find the value of y: x + y = 286 36 + y + y = 286 2y + 36 = 286 Subtract 36 from each side so we can get the variable on a side and the numbers on another: 2y + 36 = 286 2y + 36 - 36 = 286 - 36 2y = 250 Divide both sides by 2 so we can get the variable y on a side, and its value on the other: (2y)/2 = 250/2 y = 125.
In equation (1), let's replace y by it's value to find the numeric value of x: x - y = 36 x - 125 = 36 Let's 125 in each side to get x on a side and its value on the other: x - 125 + 125 = 36 + 125 x = 161
You can re-check your answer (Very important): x - y = 161 - 125 = 36 (The difference of the 2 numbers is 36) x + y = 161 + 125 = 286 (their sum is 286) The answer has been approved.
For a right triangle, the sine of an angle is the ratio of the length of the side opposite to it and the hypotenuse and the its cosine is the ratio between the side adjacent to it and the hypotenuse. From the given choices, the angle being referred to is letter B. 45°.