diketahui a dan b penyelesaian dari sistem persamaan: x -3y=-10;2x+ y=-6 jika a

x -3y = -10
x = 3y -10 ...(1)
2x + y = -6...(2)

subtitusi
2x + y = -6
2(3y-10) +y =-6
6y -20 + y = -6
7y = 14
y = 2

x = 3y -10
x = 3(2)-10
x = 6-10
x = -4

a<b
3a + 5b = 3(-4) +5(2) = -12+10 = -2