Please help will mark brainliest

Answer:
a) 3
b) -3
Step-by-step explanation:
Absolute value makes sure that whatever is in the lines will equal a positive.
Answer:
[tex]\left|4-7\right|\\\mathrm{Subtract\:the\:numbers:}\:4-7=-3\\=\left|-3\right|\\\mathrm{Apply\:absolute\:rule}:\quad \left|-a\right|=a\\=3[/tex]
[tex]\left|4\right|-7\\\mathrm{Apply\:absolute\:rule}:\quad \left|a\right|=a,\:a\ge 0\\\left|4\right|=4\\=4-7\\Simplify\\=-3[/tex]
Step-by-step explanation:
numbers that have |x| around the numbers means its an absolute number, making it positive