Answer:
19. x = 65
20. x = 12
21. x = 35, y = 85
Step-by-step explanation:
19. 2x -10 = 120
2x (-10 + 10) = (120 +10)
2x/2 = 130/2
x = 65
20. 2x + 4x + 108 = 180
6x + (108 - 108) = (180 - 108)
6x/6 = 72/6
x = 12
21. 2x + 25 = 3x - 10
2x + (25 - 25) = 3x (- 10 - 25)
(2x - 3x) = (3x - 3x) - 35
-x/-1 = -35/-1
x = 35
3x - 10 + y = 180
3(35) - 10 + y = 180
105 - 10 + y = 180
(95 - 95) + y = (180 - 95)
y = 85
Answer: 4,170
Step-by-step explanation:

Answer:
B
Step-by-step explanation:
The equation of a line in slope- intercept form is
y = mx + c ( m is the slope and c the y- intercept )
Rearrange 2x + 3y = 4 into this form
Subtract 2x from both sides
3y = - 2x + 4 ( divide all terms by 3 )
y = -
x +
← in slope- intercept form
with slope m = - 
Given a line with slope m then the slope of a line perpendicular to it is
= -
= -
=
, hence
y =
x + c ← is the partial equation of the perpendicular line
To find c substitute (- 2, 15) into the partial equation
15 = - 3 + c ⇒ c = 15 + 3 = 18
y =
x + 18 → B
Answer:
$0.125 , so 12.5 cents per pencil
Step-by-step explanation:

You can double check this by doing
, making sure it equals 3.
Answer:
y=2
Step-by-step explanation:
7y-1=13
+1 +1
7y=14
/7 /7
y=2