All you have to do is plug in 15 to f(x) to get
15=4|x-5|+3 then solve for x
12=4|x-5|
3=|x-5|
3=x-5
-3=x-5
x=8, -2
Hope this helped :)
A1=8
common ratio=r
sum of 6 terms
S=a1+a2+a3+...+a6
=a1(1+r+r^2+...+r^5)
=a1(r^6-1)/(r-1)
but we're given S=74648
=>
8(r^6-1)/(r-1)=74648
Cross multiply and solve for r (by trial and error)
r^6-1=9331(r-1)
r=6
so
a(3)=a1*r^(3-1)
=8*(6^2)
=288
Simplify 2.8y + 6 + 0.2y to 3y + 6
subtract 3y from both sides
simplify 5y - 15 - 3y to 2y - 15
add 15 to both sides
simplify 6 + 15 to 21
divide both sides by 2
switch sides
Answer: y = 21/2
*in decimal form this would be 10.5