You subtract negative 4 and negative 12...think in a number line and you find negative 4 and then you decrease( which means you move to your left of the number line) and find negative 12 and then you count the spaces you took to get to negative 12
Number one would be 13 because you have to add the x to both sides which will leave you with 2x=26 then you have to divide by 2 and you will get x=13. Number two is 7 7/8 because you have to add the 1/3x to the other 1/3x to get 2/3x= 5 1/4 so then you divide both sides by 2/3 and to divide a fraction you do keep change flip so it would be 21/4 times 3/2 which would be 63/8 which simplifys to 7 7/8.
4(a-2)=3(a+4)
4a-8=3a+12
a=20