Combining these three formulas into a comprehensive formula is: (400-43 )÷(6+ 15)

2. The sum of number A and number C is 48, and number A is 32 larger than number C. What is the number C?

Column synthesis formula: (48-32)÷2

3. It is known that 240 ÷ 8 = 30,132+30 =162,262-162 =100.

Combine these three formulas into a comprehensive formula: 262-( 132+240÷8).

4. It is known that 42× 100 = 4200, 17+83 = 100, 4200+78 = 4278.

Combining these three formulas into a comprehensive formula is 42×( 17+83)+78.