Answer:
0.143
Step-by-step explanation:
7 / 7³ x 7 Start with the exponents first
7 / 343 x 7 Divide 7/343
0.02 x 7 Multiply 0.02 x 7
7^(1-3+1) = 7^-3
Here is the rule you should know: when multiplying powers of the same base you add the exponents ans when dividing powers of the same base you subtract the exponents.
Also, if there is no number at the exponent, it is 1.
i think its 21/x-4
sorry if im wrong
4 ( b + 5 )- 2b = 100
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B = 40