Answer:

Step-by-step explanation:

Add
and
on both sides.

Add or subtract like terms.

Divide
on both sides.


is the independent variable now.
Answer:
Step-by-step explanation:
a + 143 = 180 {Linear pair}
a = 180 - 143
a = 37
37 + 93 + b = 180 {Angle sum property of triangle}
130 + b = 180
b = 180 - 130
b = 40
c + b = 90
c + 40 = 90
c = 90 - 40
c = 50
d + 120 = 180 {Linear pair}
d = 180 - 120
d = 60
? = 60 + 40 {Exterior angle property of triangle}
? = 100
You can tell that a line is parallel if the lines can go on forever without crossing or intersecting. A line is perpendicular when the lines intersect at a right angle. If the slopes are either equal or negative reciprocals, they cannot be parallel or perpendicular.
Hope this helps you!
61 would be the most simplified without expressions
Put the first equation in slope-intercept form, or y = mx + b. Start by subtracting y from both sides.
2x - y = -10, subtract 2x from both sides.
-y = -10 - 2x
Divide both sides by negative one.
y = 10 + 2x
To find the slope when the equations are in slope-intercept form you look at the coefficient of x. The first equation has the slope of 2 (which we just found), and the second equation has the slope of -2.
Parallel lines have the same slope and perpendicular lines have opposite reciprocal slopes. Since 2 and -2 are neither of these, your answer is neither.