For the first one:
m is the slope, or how much the line goes up compared to goes right. In this case, the line goes up 40 every time it goes right 10. We write this as a fraction so 40/10, which simplifies to 4. Therefore the equation would be y = 4x.
Well do you know what a supplementary angles is ?
it is two angles that add up to 180 degrees
When added, these two angles are supplementary, meaning that their sum is 180. This means that we can do the following to find x, and eventually DBC:
3x+67+4x+50=180
Simplifies to:
7x+117=180
Then by the Subtraction Prop. of Equality:
7x=63
Then divide by 7 on both sides to get that x=9.
We then substitute 9 into angle DBC.
4(9)+50
=36+50
DBC=86
:)
93.96. You multiply them together to get the answer.