supplementary angles add up to 180°.
x = measure of such angle
x + 20 = measure of her sibling.
since "x" has 20 less than her sibling, then clearly her sibling has to have 20 more than "x".

Answer:
y ≤ x - 1
Step-by-step explanation:
The slope is 1 (every unit for x, there is a unit for y, rise/run is 1/1). The y-intercept is -1, because the line crosses the y-axis at -1. The graph is shaded below the line, and the line is solid, meaning that y is less than or equal to x -1, or y ≤ x - 1.
X 25*24*23*22*21*20*19
which gives you
2,422,728,000
Is there a problem equation?