Question:
Yuet solved the equation
for a.
Her steps are shown below.
1. Subtract 2b: 
2. Divide by 6: 
Answer:
In step 1 she needed to add 2b to both sides of the equation.
Step-by-step explanation:
Given:
The above steps shows how Yuet solved an equation
Required:
True statement about Yuet's work
The implication of the statement is to state what Yuet should have done instead of what she did.
In step 1, she subtracted 2b from both sides of the equation; this is wrong.
Instead of subtracting, she ought to add 2b to both sides of the equation.
The correct steps and result is as follows:
1. Add 2b: 
2. Divide by 6: 
Hence, we can conclude that in step 1 she needed to add 2b to both sides of the equation.
Answer: x > 18/7
Step-by-step explanation:
The answer is equivalent to 10*9*8 as their is one less student to go after each presentation.
720 ways.
Answer:
E. -8, -29
Step-by-step explanation:
a-b=21
5a -2b =18
Take the first equation and solve for a by adding b to each side
a-b=21
a-b+b=21+b
a = 21+b
Now substitute a=21+b into the second equation
5a -2b =18
5(21+b) -2b =18
Distribute the 5
105 +5b-2b =18
Combine like terms
105 +3b =18
Subtract 105 from each side
105-105 +3b = 18-105
3b = -87
Divide each side by 3
3b/3 =-87/3
b = -29
if b = -29, we can substitute it into a =21+b
a = 21-29
a = -8