Answer:
x = 7
Step-by-step explanation:
12x - 16 = 68
Add 16 to each side
12x - 16+16 = 68+16
12x =84
Divide by 12
12x/12 = 84/12
x = 7
Answer:
as written: 7x^2
perhaps intended: 7x^4
Step-by-step explanation:
As written, the Order of Operations specifies that the only denominator factor is 3, so the expression is interpreted as ...

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Sometimes grouping of denominator factors is intended, but parentheses are not written as they should be. If the intention is ...
21x^3/(3x^-1)
then the simplification is ...

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The applicable rules of exponents are ...
(a^b)(a^c) = a^(b+c)
a^b/a^c = a^(b-c)
In order to find b1 from your formula stated we need to do few calculations
A=hb1+hb2, as you wee I multiply h with both bases( b1 and b2)
I will subtract hb2 from both sides
hb1=A-hb2
now I will divide my new expression by h
b1=(A-hb2)/h