Answer:

Step-by-step explanation:
Slope-intercept from is:

m is the slope and b is the y-intercept. Insert slope:

The y-intercept is at point (0,4). The y-intercept is when x equals 0, so take the value of y and insert into the equation:

Finito.
Answer:
7 1/6
Step-by-step explanation:
I think it is because they are both different differences
Answer:
7. x = 5
8. x = 2, y = 6
9. x = 21, y = 39
Step-by-step explanation:
For a parallelogram, the lengths across intersection are equal.
7. For a parallelogram, the lengths across intersection are equal.
So that,
3x = 4x - 5
4x - 3x = 5
x = 5
8. For a parallelogram, the lengths across intersection are equal.
So that,
2x = 4
x = 
x = 2
and
y - 1 = 2y -7
7 - 1 = 2y - y
y = 6
x = 2, y = 6
9. For a parallelogram, opposite angles have equal value.
Thus,
3x = (4x - 21)
3x = 4x - 21
x = 21
and
3y = (y + 78)
3y = y + 78
3y - y = 78
2y = 78
y = 
= 39
y = 39
x = 21, y = 39
You are solving quadratic equations. to do so, use the quadratic formula when possible, or factor. 15- for example, you can factor (x+5)(x+3), therefore x=-5,-3. You then go back and plug in your answers to see if you can eliminate any of them.