Answer: x=8
Explanation:
Since we are given that ∠ABC and ∠DBC are complementary angles, we know that adding them together should give us 90°. We can use this to solve for x.
6x+13+4x-3=90 [combine like terms]
10x+10=90 [subtract both sides by 10]
10x=80 [divide both sides by 10]
x=8
Now, we know that x=8.