The solution equation is 40x + 21 = 37 X - 78x = 2.2 x + 30x = 26 (1 - 25%) x = 15 2x + 20x = 3.3

The solution equation is 40x + 21 = 37 X - 78x = 2.2 x + 30x = 26 (1 - 25%) x = 15 2x + 20x = 3.3

1: 40x% + 21 = 37 multiply both sides by 100 to get: 40x + 2100 = 3700
40X=3700-2100 40X=1600 X=40 .
2: X-78x% = 2.2 multiply both sides by 100 to get 100x-78x = 220
22X=220 X=10 .
3: X + 30x% = 26 multiply both sides by 100 to get: 100x + 30x = 2600
130X=2600 X=20 .
4: (1-25%) x = 15 x-25x% = 15 multiply both sides by 100 to get:
100X-25X=1500 75X=1500 X=20 .
5: 2X + 20x% = 3.3 multiply both sides by 100 to get: 200X + 20x = 330
220X=330 X=1.5 .