1 answer:
Answer:
The step 4 is not what he should have done. But the wrong is step 5, because if he added -2x both sides, it would give the following equation:

and not 
Note that in step 4 he should have added 2x and not -2x to both sides, but we still have the equality. The problem is that step 5 is totally wrong.
I don't know what answer is expected to this question, but I would mark step 5, because this is mathematically wrong.
Solving the equation

Using distribution

Add
both sides


Add 12 both sides

Divide both sides by 5

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It should be about (5,5.5)
Answer:
0.75
Step-by-step explanation:
Time = D/S
D = 1.4 km
S = 112km/h
Time = 14/1120
=1/80
1/80 × 60 ( 1 hour =60 s)
=0.75 second
The correct answer is D.
X=7
8=7+1
8=8
They are called the order of operations, or PEMDAS. Hope this helps!