Question

Quadrilateral ABCD is a rectangle. If m /_DBC = 10x and m /_ACB = 4x^2-6, find m /_ACB​

Answer 1

5

Explanation:

m∠DBC = m∠ACB

4
`x^(2)`-6=10x

4
`x^(2)`-10x-6=0

(4x-2)(x+3)=0

x =
`(1)/(2)` or -3

The angle can't be negative.

∴ x =
`(1)/(2)`

m∠ACB = 4
`x^(2)` = 10x = 10 X
`(1)/(2)`= 5

I hope it helps you!