Question

Find the exact solution of x
3x^2+7=28
A.+√7
B.7
C.+7
D.-7

Answer 1

A. +
`√(7)`

Explanation:

3x^2+7=28
3(
`+√(7) ^(2)` )+7=28

3(7)+7=28

21+7=28
28=28

Hope it helps

Answer 2

x = ±
`√(7)`

Explanation:

3x² + 7 = 28 ( subtract 7 from both sides )

3x² = 21 ( divide both sides by 3 )

x² = 7 ( take square root of both sides )

x = ±
`√(7)`

that is x = -
`√(7)` , x =
`√(7)`