Answer: X = 8
9 + X = 17; Subtract 9 from both sides
X = 8
Check: Place 8 in for X
9 + (8) = 17
17 = 17; True, so answer is right
15) x^2-2x-8=1/4x-1
x^2-2.25x-7=0
4x^2-9x-28=0
(x-4)(4x+7)=0
x-4= 0 or 4x+7=0
x=4 or x= -7/4=-1.75
16) answer hides in the f(x) equation
the trick is to think of the value that will make the (x-4) =0 and and the y value can be directly plugged off from the +c
therefore, ans is x=2 y= 4
(2,4)
Let the number that wll be added be x, then
-7/9 + x = 5
x = 5 + 7/9 = 5 7/9 or 52/9