Question

Which equation can be used to determine the value of x?

(6x + 2) + 40 = 90
(6x +2) + 40 = 180
None of these
(6x + 2) = 40
All of these

Answer 1

Complementary angles have sum 90°

Hence

• 6x+2+40=90

Option A

• 6x+42=180
• 6(x+7)=6(30)
• x+7=30
• x=23

Answer 2

A)(6x + 2) + 40 = 90

Explanation:

(for convenience, I have labelled it with alphabets)

Line ED has crossed line AB perpendicularly resulting
`\angle BFC` and
`\angle CFD` complimentary to each other. That means

`\angle BFC+\angle CFD=90^(\circ)`

Here:

• 
  `\angle BFC=(6x+2)^(\circ)`
• 
  `\angle CFD=40^(\circ)`

Hence,

The equation can be used to determine the value of x is

• (6x + 2) + 40 = 90

In conclusion

Our answer is A)