Find the value of x, please help me :)

Solve: 3x+y=6 4x-2y=18 show all work !

Grandpa ernie is shrinking! over the past 4 years his height decreased by a total of 2.4 cm.it decreased by the same amount each year. what was the change in grandpa ernie's height each year

An art teacher made a copy of a small painting. to make the painting easier to see the teacher enlarged the area of the painting by 49%. let y respresent the area of the original painting. the expression below is one way to resperesnt the area of the new painting.find two equivalent expressions that would give the area of the new painting y+0.49y