Solution:
firstly solve parenthesis bracket ( )
-4×3 + 4×5x ≥ -6x + 9
-12 + 20x ≥ -6x + 9
Add 12 on both sides
-12 + 12 + 20x ≥ -6x + 9 + 12
20x ≥ -6x + 21
Add 6x on both sides
6x+ 20x ≥ -6x + 6x + 21
26x ≥ 21
divide both side by 26
26 x/26 ≥21/26
x ≥21/26
