Question

Can someone help pls

Answer 1

x=5

Explanation:

Here,

→
`2x^(2) +21=3x^(2) -4\\\\`

→
`21+4=3x^(2) -2x^(2) \\`

→
`x^(2) =25`

→
`x=√(25)`

→
`x=5`

Let's check whether they are equal or not by putting the value of x.

→
`2x^(2) +21`

→
`(2*5^(2)) +21`

→
`50+21`

→
`71`

→
`3x^(2) -4`

→
`(3*5^(2) )-4`

→
`75-4`

→71

Hence they are equal.

Answer 2

x = ± 5

Explanation:

for the figure to be an isosceles trapezoid

then the lower base angles must be congruent , that is

3x² - 4 = 2x² + 21 ( subtract 2x² from both sides )

x² - 4 = 21 ( add 4 to both sides )

x² = 25 ( take square root of both sides )

x = ±
`√(25)` = ± 5