-12 = 4x + 8, with x representing the number
Minus eight from both sides
-20 = 4x
Divide both sides by four
x = -5
2 #'s whose sum is 51: x + y = 51
2 #'s whose difference is 13: x - y = 13
add the 2 equations: 2x = 64 ⇒ x = 32
using either equation find y: 32 + y = 51 ⇒ y = 19
Answer the 2 #'s are 32 and 19
Answer:
1/2 3/6 4/8 and 5/10 because all are equivalent to 2/4
38 words because for every week he practices his words per minute increase by 4
