Simplify the following expressions
a) 7x + 2y + x + 3y
b) x + 7y + 10x - 15y
HELP ​

50 ! pls ! 12.  building codes regulate the steepness of stairs. homes must have steps that are at least 13 inches wide for each 8 inches that they rise.

a. discuss how to find the slope of the stairs.
b. describe how changing the width or height affects the steepness of the stairs.

If the slope of one line equals the slope of another line then ? a) the two lines are intersecting lines b) the two lines are perpendicular lines c) the two lines are parallel lines d) the two lines always have very steep slopes

8000 + 8800 + 8000 + 8 million + 80 trillion + another a katrillion equals