N4=c
n times 4, n being a number of notebooks, would equal c, or the overall cost.
What multiplies to 25 and adds to -10
-5 and -5
(x-5)(x-5)
(x-5)²
P1=2.5+2.5+4.75+4.75=14.5 cm
0.5 cm - 1 in
2.5 cm - 5 in
4.75 cm - 9.5 in
P2=5+5+9.5+9.5=29 in
First find the slope:
y-y/x-x
5-0/0-(-10
5/+10
slope: 1/2
then use:
y-5. 1
--- = ---
x-0. 2
cross multiply.
2 (y-5)=1 (x-0)
2y-10=x
move the ten to the other side, switch the sign
2y=x+10
divide by 2
y=1/2x+5
final answer is
y=1/2x+5
