∣10x+4∣≤1|10 x+4| \leq 1∣10x+4∣≤1
∣10x∣<1|10 x|<1∣10x∣<1
∣10x−4∣<1|10 x-4|<1∣10x−4∣<1
∣5x+2∣<1|5 x+2|<1∣5x+2∣<1
