Subtract 5 from both sides
a/-8 = 4/7 - 5
simplify 4/7 - 5 to 31/-7
a/-8 = 31/-7
multiply both sides by 8
-a = 31/-7 x 8
simplify 31/7 x 8 to 248/7
-a = 248/7
multiply both sides by -1.
The answer is a = 248/7
The words are the explanations of the steps and the dark bolded words are the work shown for each step.
Certain means the event will happen.
Impossible means the event would never happen.

==================================
<em />
<em>"Associate with people who are likely to improve you."</em>
1. b
2. e
3. a
4. c
5. d
6. f
7. g
8. h
hope this helps there is really no way of explaining you would have to study you theorems
$1.50C + $4A= $5050
C + A = 2200
-4(C + A = 2200)
-4C - 4A = -8800
1.50C+4A = 5050
-----------------------
-2.5C =- 3750
-2.5C/-2.5 =- 3750/-2.5
C = 1500
C + A = 2200
1500 + A =2200
1500 - 1500 + A = 2200 - 1500
A = 700
CHECK
$1.50C + $4A= $5050
$1.50(1500) + $4(700)= $5050
$2250 +$2800 =$5050
$5050 = $5050
C + A = 2200
1500 + 700 =2200
2200 = 2200