Iknow this should be easy for people in my grade, but it isn't for me, some one

0.7x - 1.4 = -3.5 (combine like terms, -1.4 and -3.5)
+1.4 (you do this on both sides of the equal sign, 1.4 will cancel out on the left)

0.7x = -2.1 (-3.5 + 1.4 = -2.1, now you get "x" by itself)
 ÷0.7 (divide 0.7 on both sides, it cancels out and leaves the "x" alone)

x = -3 (-2.1 ÷ 0.7 = -3, so the value of "x" is -3) 

I hope this helped. Goodluck! ☺♥