4b × 25 × 79x + 7x + 3x - 52x - 16x + 9x - 7(2x + 3) - 10x= 4b × 1975x + 7x + 3x - 52x - 16x + 9x - 14x - 21 - 10x= 7900bx - 63x - 21 - 10x= 7900bx - 73x - 21
4b × 25 × 79x + 7x + 3x - 52x - 16x + 9x - 7(2x + 3) - 10x
= 4b × 1975x + 7x + 3x - 52x - 16x + 9x - 14x - 21 - 10x
= 7900bx - 63x - 21 - 10x
= 7900bx - 73x - 21