Question

A=2b^3-1 what's the value of b if a is 13

Answer 1

A = 2b³ - 1
13 = 2b³ - 1
+ 1 + 1
14 = 2b³
2 2
7 = b³
∛(7) = b

Answer 2

`\sf~A=2b^3-1`

Plug in A = 13


`\sf~13=2b^3-1`

Add 1 to both sides:


`\sf~14=2b^3`

Divide 2 to both sides:


`\sf~7=b^3`

Find the cube root of both sides:


`\sf~b=\sqrt[3]{7}`


`\sf~b\approx~1.91`