The simplified form is 6x-6
Answer:
24 years old
Step-by-step explanation:
Let the age of Blake be x and the age of Heather by y then...
x=7+y
7+x+7+y=55
Notice we are adding additional 7s because the question states "in 7 years"
Simplify the second equation...
7+x+7+y=55
14+x+y=55
Subtract 21 from both sides
x+y=41
Solve using substitution (substitute 7+y for x since x = 7+y)
7+y+y=41
Combine like terms
2y+7=41
Subtract 7 from both sides
2y=34
Divide both sides by 2
y=17
x=7+17=24
Blake is 24 years old now
Answer:
B) the cube of 4 and then take the square root
Step-by-step explanation:
43/2 = 21.5
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The answer choices suggest you want ...
4^(3/2) . . . . . . . appropriate math symbols are very helpful
This can be evaluated several ways:

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Since the 3 is in the numerator of the fraction, it represents a cube, not a cube root. Any of the answer choices suggesting cube root is involved are incorrect. (Eliminating those leaves only the correct answer choice.)
I think the answer is B.
Hope this helps.