4 - c = 1/3...multiply everything by 3
12 - 3c = 1
-3c = 1 - 12
-3c = -11
c = 11/3 <==
================
-14 = x - 12
-14 + 12 = x
-2 = x <==
================
s / 1.5 = 0.8...multiply both sides by 1.5
s = 0.8 * 1.5
s = 1.2 <==
===============
0.4r = 1.6...divide both sides by 0.4
r = 1.6 / 0.4
r = 4 <==
===============
2d - 15 = 3
2d = 3 + 15
2d = 18
d = 18/2
d = 9 <==
===============
4 = 3/4m - 6...multiply by 4
16 = 3m - 24
16 + 24 = 3m
40 = 3m
40/3 = m <==
===============
-3(n + 6) + 10 = -8
-3n - 18 + 10 = -8
-3n - 8 = -8
-3n = -8 + 8
-3n = 0
n = 0 <==
===============
1.5(q - 4) - 2 = 4
1.5q - 6 - 2 = 4
1.5q - 8 = 4
1.5q = 4 + 8
1.5q = 12
q = 12 / 1.5
q = 8 <=
================
1/3x + x - 20 + x - 10 + 40 = 360
1/3x + 2x + 10 = 360
1/3x + 6/3x = 360 - 10
7/3x = 350
x = 350 * 3/7
x = 150
< 1/3x is (1/3 * 150) = 150/3 = 50 degrees
< x - 20 is (150 - 20) = 130 degrees
< x - 10 is (150 - 10) = 140
< 40 = 40 degrees
========================
1/2x + 1/2x + x - 15 + x - 25 + 100 = 540
3x + 60 = 540
3x = 540 - 60
3x = 480
x = 480/3
x = 160
< 1/2x is (1/2 * 160) = 160/2 = 80 degrees
< 1/2x is 80 degrees
< x - 15 is (160 - 15) = 145 degrees
< x - 25 is (160 - 25) = 135 degrees
< 100 is 100 degrees
=====================
110 = 10a - 20
110 + 20 = 10a
130 = 10a
130/10 = a
13 = a <== he spent $ 13 on ads
====================
0.5x + 45 + x + 2x = 150
3.5x + 45 = 150
3.5x = 150 - 45
3.5x = 105
x = 105 / 3.5
x = 30
0.5x is (0.5 * 30) = 15 ft
45 ft
2x is (2 * 30) = 60 ft
30 ft
======================
60x = 360
x = 360/60
x = 6 hrs <==
======================
(8 + 9 + 12 + c) / 4 = 10
(29 + c) / 4 = 10
29 + c = 10 * 4
29 + c = 40
c = 40 - 29
c = 11 <== he would have to sell 11 cars in the 4th month