Answer:
160
Step-by-step explanation:
there are 24 first class seats. 15% of the total number is 24. that would mean 5% of the total number is 8. 20 times 8 is 160.
Step 1: -4(3x-1) becomes -12x+4
step 2: -12x+4=12-8x
step 3: add 12x to both sides, 4=12+4x
step 4: subtract twelve from both sides -8=4x
step 5: divide by 4, x=-2