pake caranya ya.... no. 14,15,sama 16

m=4/2=2
y=mx+c
1=2(2)+c
1=4+c
c=1-4
c=-3

y=2x-3
y-2x=-3 (d)



y=mx+c
-4=3(6)+c
-4=18+c
c=-4-18
c=-22

y=3x-22 (a)


2x-5y+12=0 |×5| 10x-25y+60=0
5x-2y+9 =0 |×2| 10x-4y+18=0
---------------------- _
-21y=-42
y=2
2x-5y+12=0 |×2| 4x-10y+24=0
5x-2y+9=0 |×5| 25x-10y+45=0
_____________ -
-21x=21
x=-1

3x-4y=3(-1)-4(2)
=-3-8=-11(c)