Question 161985
When x is doubled we write it as 2x and replace the x value with 2x

y=4(2x)  y=8x  The y value is also doubled  8x/4x=2

When x is increased by 2

y=4(x+2)   y=4x+8  The y value is increase by 8 units

When x is decreased by 3

y=4(x-3)  y=4x-12

The y value decreases by 12 units

When x is halved x/2

y=4(x/2)

y=2x The y values are also halved.