Answer:
According to Bodmas rule, if an expression contains brackets ((), {}, []) we have to first solve or simplify the bracket followed by of (powers and roots etc.), then division, multiplication, addition and subtraction from left to right.
Step-by-step explanation:
-4x + 20 +3a - 21
3a - 4x - 1

P. S. The inequality sign changed or flipped when there's a negative figure involved.
Hope this helps. - M
Answer:
9x + 3 = 7x + 19
Step-by-step explanation:
Given that,
Jeffrey set up chairs for a meeting.
He arranged the chairs in 9 equal rows but had 3 chairs left over.
Let x be the number of chairs. So,
9x+3 .....(1)
Then he arranged the chairs in 7 equal rows but had 19 chairs left over. So,
7x+19 ......(2)
From equation (1) and (2),
9x+3 = 7x+19
9x-7x = 19-3
2x = 16
x = 8
Hence, the correct option is (b).