The digit in the hundred millions place is 9.
Angle 1 and 2 are supplementary angles and need to equal 180 degrees
so angle 1 + angle 2 = 180:
6x+50 + 4x+40 = 180
combine like terms:
10x + 90 = 180
subtract 90 from each side:
10x = 90
divide both sides by 10
x = 9
You turn an improper fraction to a decimal by dividing the numerator (number on top) by the denominator (number under).
Angle 6 and Angle 7 are each 90° since they’re on a straight line and are both equal.
180-90= 90
*you subtract from 180 because that’s how many degrees are in a straight line*
Angle 7 and Angle 1 are alternate exterior angles so that makes them congruent by definition.