x = unknown number (that is a solution/makes the inequality true)
When the inequality sign is </> (less than/greater than), the dot is an open circle.
When the inequality sign is ≤/≥ (less than or equal to/greater than or equal to), the dot is a closed circle.
14.) The line has an open circle on -8, and a closed circle on 11.
-8 < x ≤ 11 [x is any number greater than -8 and less than or equal to 11]
15.) The line has a closed circle on -14 and 5.
-14 ≤ x ≤ 5 [x is any number greater than or equal to -14 and less than or equal to 5]
F(x)=(x-8)/(x+7). g(x)=(-7x-8)/(x-1). Plug in g(x) into f(x), f(g(x))=[(-7x-8)/(x-1)-8]/[-7x-8)/(x-1)+7], which can be simplified as (-7x-8-8x+8)/(-7x-8+7x-7)=-15x/-15=x. Plug in f(x) into g(x), g(f(x))=[-7*(x-8)/(x+7)-8]/[(x-8)/(x+7)-1]=(-7x+56-8x-56)/(x-8-x-7)=-15x/-15=x, as desired.
x+y=120_______1
x=4*y_________2
x=4y
substitute 4y for x in equation 1
`4y+y=120
5y=120
eliminate the coefficient of y
y=120/5
y=24
now,input 24 for y in equation 2
`x=4y
x=4*24
x=96
thus, the numbers are
96 and 24