Hi,
We start plugging in the value of 1.
12 + [20(5-k)]
First of all solve the brackets, by appling the distributive property.
20*5 and 20*k
12 + [20(5-1)]
12 + (100 - 20)
12 + 80 = 92
You can also solve by subtracting
12 + [20(4)]
12 + 80 = 92
For the second one, an absolute value is a number always positive.
24 : |4-10| = 24 : |-6| = 24 : 6 = 4