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
Answer:
2 miles
Step-by-step explanation:
Their combined speed (speed of closure) is 80 mph + 40 mph = 120 mph.
120 mi/h = 120 mi/(60 min) = 2 mi/min
The distance between the trains at the 1-minute mark is ...
(1 min) · (2 mi/min) = 2 mi
They were warned when two miles apart.
25/100 = 1/4 (divide both numerator and denominator by 25)
350/1000 = 35/100 = 7/20.
Answer:
A
Step-by-step explanation:
Sum the parts of the ratio, 5 + 3 = 8 parts
Divide the total area by 8 to find the value of one part of the ratio.
1624 ÷ 8 = 203 cm² ← value of 1 part of ratio, thus
Area of B = 3 × 203 = 609 cm² → A
Answer:
$10.45
Step-by-step explanation:
14.95 divided by 1.43 = 10.50
